Control method of information terminal and 
computer-readable recording medium

ABSTRACT

A medical image managed by a medical information management system is displayed in a layout region that is displayed on a display of an information terminal, and thumbnail images of similar cases received from a case retrieval system are displayed in a case display region. In the layout region, a display box displaying a thumbnail image of a diagnosis object case and display boxes displaying thumbnail images selected from the thumbnail images displayed in the case display region are displayed adjacent to one another.

TECHNICAL FIELD

The present disclosure relates to a control method of an informationterminal for retrieving a similar medical image which is similar to amedical image of a diagnostic interpretation object and acomputer-readable recording medium.

BACKGROUND ART

In recent years, we have seen the development and implementation ofmedical imaging apparatuses that perform CT (Computed Tomography), MRI(Magnetic Resonance Imaging), and the like. CT, MRI, and the like enableacquisition of digitalized high-resolution medical images in largeamounts. In addition, medical images after being diagnosticallyinterpreted by a radiologist are sequentially accumulated in PACS(Picture Archiving and Communication Systems) together with a diagnosticinterpretation report. Meanwhile, as disclosed in Patent Literature 1for example, techniques have started to be developed for retrieving pastmedical images which are similar to a medical image of a diagnosticinterpretation object from past cases accumulated in PACS to be used asa reference when newly performing a diagnostic interpretation.

However, further improvements are required.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Unexamined Patent Publication No.    2008-257292-   Patent Literature 2: Japanese Unexamined Patent Publication No.    2012-35124

Non Patent Literature

-   Non Patent Literature 1: Akira Oosawa and four others, “Development    of “SYNAPSE Case Match”, Content-based Image Retrieval System for    Supporting Image Diagnosis”, Fujifilm Research & Development,    FUJIFILM Corporation, Mar. 27, 2013, No. 58, pp. 11-14.

SUMMARY OF INVENTION

In one general aspect, the techniques disclosed here feature a controlmethod of an information terminal, which is connected to a medicalinformation management system that manages medical images that arediagnostic interpretation object candidates, and which is connected to acase retrieval system that refers to a medical image database in whichmedical images are registered and retrieves a medical image, andmoreover which includes a display,

one medical image that is a diagnostic interpretation object selectedfrom the diagnostic interpretation object candidates managed by themedical information management system being displayed on the display,

the control method causing a computer of the information terminal to:

sense specification information indicating a region of interest in themedical image;

receive from the case retrieval system one or more similar medicalimages each having a prescribed degree of similarity with a featurequantity of the region of interest indicated by the specificationinformation in accordance with the region of interest;

display the medical image that is managed by the medical informationmanagement system in a first display region of a first display screenthat is displayed on the display and display thumbnail views of aplurality of similar medical images received from the case retrievalsystem in a second display region that differs from the first displayregion of the first display screen, the first display region including afirst display box for displaying the medical image and a second displaybox for displaying a first similar medical image selected from thesimilar medical images displayed in thumbnail views in the seconddisplay region, the first display box and the second display box beingadjacent to each other; and

when sensing an operation for moving the first similar medical imageamong the similar medical images displayed in thumbnail views in thesecond display region to the second display box, display the firstsimilar medical image in the second display box and display the firstsimilar medical image so as to be adjacent to the medical image.

According to the aspect described above, further improvements can beachieved. These general and specific aspects may be implemented using asystem, a method, and a computer program, and any combination ofsystems, methods, and computer programs.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an overall configuration diagram of a hospital informationsystem to which an information terminal according to a presentembodiment is applied.

FIG. 2 is a block diagram showing configurations of an informationterminal, a medical information management system, and a case retrievalsystem.

FIG. 3 is an external view of two displays.

FIG. 4 is a diagram showing a configuration example of an implementationof an information terminal.

FIG. 5 is a diagram showing an example of a basic screen that isdisplayed on a display immediately after starting a similar caseretrieval application on an information terminal.

FIG. 6 is a diagram showing an example of a basic screen that isdisplayed on a display immediately after starting a similar caseretrieval application on an information terminal.

FIG. 7 is an extracted view showing a display region of one similar casethat is displayed in a case display region.

FIG. 8 is an enlarged view of a disease name list display region.

FIG. 9 is a diagram showing a basic screen when similar cases arenarrowed down by “mycosis”.

FIG. 10 is a diagram showing a basic screen when similar cases arenarrowed down by “metastatic lung cancer”.

FIG. 11 is an enlarged view of a distribution list display region.

FIG. 12 is a diagram showing a distribution list display region in whicha check mark is input.

FIG. 13 is a diagram showing a basic screen having been narrowed down bya bronchial lesion distribution.

FIG. 14 is a diagram showing a distribution list display region in whicha plurality of check marks are input.

FIG. 15 is a diagram showing a basic screen having been narrowed down bya plurality of lesion distributions.

FIG. 16 is a flow chart showing a process for registration to historyinformation.

FIG. 17 is a diagram showing an example of history information stored ina history information managing unit.

FIG. 18 is a diagram showing a basic screen displaying a historymanagement region.

FIG. 19 is a diagram showing a basic screen displaying a historymanagement region in which a display space is expanded to two rows.

FIG. 20 is a diagram showing a history management region in which ascroll bar is displayed.

FIG. 21 is a diagram showing a basic screen in a case when a mode thatdisplays a history management region from an initial state is adopted.

FIG. 22 is a diagram showing a data configuration of patientinformation.

FIG. 23 is a diagram showing a data configuration of examinationinformation that is registered in the patient information shown in FIG.22.

FIG. 24 is a diagram showing a data configuration of a medical imagedatabase.

FIG. 25 is a diagram showing a data configuration of a diagnosticreport.

FIG. 26 is a diagram showing a data configuration of similar case data.

FIG. 27 is a diagram schematically showing a region of interest set in aslice image.

FIG. 28 is a sequence diagram showing a process in which an informationterminal first acquires a diagnosis object case from a medicalinformation management system and then issues a request for similar caseretrieval to a case retrieval system, and the case retrieval systemsubsequently receives the request for similar case retrieval.

FIG. 29 is a screen diagram of an examination list.

FIG. 30 is a screen diagram of an examination list after an examinationis selected.

FIG. 31 shows an example of a screen after a region of interest has beenset with respect to a lesion.

FIG. 32 is a sequence diagram showing a process in which, after a caseretrieval system receives a request for similar case retrieval, the caseretrieval system sends back a similar case retrieval result to aninformation terminal.

FIG. 33 is a flow chart showing details of a process for generating aninitial basic screen shown in S670 in FIG. 32.

FIG. 34 is a flow chart showing a process of S1500 shown in FIG. 33.

FIG. 35 is a diagram showing a data configuration of a disease name listthat is generated in S1300 in FIG. 33.

FIG. 36 is a diagram showing a first display example of a disease namelist display region.

FIG. 37 is a diagram showing a second display example of a disease namelist display region.

FIG. 38 is a diagram showing a third display example of a disease namelist display region.

FIG. 39 is a diagram showing a screen transition of the disease namelist display region shown in FIG. 37.

FIG. 40 is a diagram showing a data configuration of a distribution listthat is generated in S1400 in FIG. 33.

FIG. 41 is a diagram showing a basic screen having a layout region inwhich display boxes are set in three rows and two columns.

FIG. 42 is a diagram showing an example of layout managementinformation.

FIG. 43 is a diagram showing an example of layout managementinformation.

FIG. 44 is a diagram showing a data configuration of display boxmanagement information.

FIG. 45 is a flow chart showing a starting process of a medical imageviewer.

FIG. 46 is a block diagram of an information terminal, a medicalinformation management system, and a case retrieval system when a modeis adopted in which the case retrieval system extracts an image feature.

FIG. 47 is a sequence diagram showing a process in which, after aninformation terminal acquires a diagnosis object case from a medicalinformation management system, a case retrieval system receives arequest for similar case retrieval.

FIG. 48 is a sequence diagram showing a process in which, after a caseretrieval system receives a request for similar case retrieval, the caseretrieval system sends back a similar case retrieval result to aninformation terminal.

FIG. 49 is a sequence diagram showing a process when a thumbnail imageof a similar case is dragged and dropped on an information terminal.

FIG. 50 is a flow chart showing details of a process of S800 shown inFIG. 49.

FIG. 51 is a diagram showing a basic screen when one thumbnail imageamong thumbnail images displayed in a case display region is selected.

FIG. 52 is a diagram showing the one thumbnail image selected in FIG. 51being dragged.

FIG. 53 is a diagram showing a basic screen on which a color of adisplay box has been changed.

FIG. 54 is a diagram showing a basic screen when a thumbnail image isdisplayed in a layout region.

FIG. 55 is a diagram showing display box management information in whicha slice ID of a similar case has been registered.

FIG. 56 is a diagram showing a basic screen of a display when a sliceimage is displayed on a medical image viewer.

FIG. 57 is a diagram showing a display relationship between twodisplays.

FIG. 58 is a diagram showing a display relationship between twodisplays.

FIG. 59 is a diagram showing a display relationship between twodisplays.

FIG. 60 is a diagram showing a display relationship between twodisplays.

FIG. 61 is a diagram showing a basic screen in a state in which alldisplay boxes are filled with thumbnail images and another thumbnailimage is being dragged.

FIG. 62 is a diagram showing a basic screen on which a mark is displayedon a display box.

FIG. 63 is a flow chart showing a modification of FIG. 50.

FIG. 64 is a sequence diagram when focusing on the sequence diagramsshown in FIGS. 28 and 32 on an application level.

FIG. 65 is a sequence diagram when focusing on the sequence diagramshown in FIG. 49 on an application level.

FIG. 66 is a sequence diagram which focuses, on an application level, ona process when a thumbnail image of a similar case isdragged-and-dropped in an information terminal.

FIG. 67 is a flow chart showing a process when a lesion distributiondisplayed in a distribution list display region is selected.

FIG. 68 is a diagram showing a basic screen when first distributioninformation is selected.

FIG. 69 is a diagram showing a basic screen when second distributioninformation is selected.

FIG. 70 is a diagram showing a basic screen when third distributioninformation is selected.

FIG. 71 is a diagram explaining a pleural region.

FIG. 72 is a diagram showing a data configuration of similar case datato which pleural region information has been added.

FIG. 73A is a diagram showing a display example of a second displayscreen.

FIG. 73B is a diagram showing a display example of a second displayscreen.

FIG. 73C is a diagram showing a slice image that is displayed on adisplay when a series is selected by a user.

DETAILED DESCRIPTION

(Circumstances Leading to the Invention of an Aspect of the PresentDisclosure)

First, viewpoints of an aspect according to the present disclosure willbe described.

Patent Literature 1 discloses an image diagnosis supporting apparatusthat presents a case image useful for determining a disorder duringimage diagnosis based on a diagnosis object image, or statisticalinformation related to the disorder, or the like. A screen of aretrieval result by the image diagnosis supporting apparatus displays adiagnosis object image and information on a representative case for eachdisorder. Specifically, the screen of the retrieval result displays i)images of representative cases of top three disorders A, D, and 0, ii) adegree of similarity with a diagnosis object image, the number ofregistered cases, and the number of representative cases for eachdisorder, iii) the number of retrievals (total number of retrieveddisorders), and iv) a “next page” software button and the like forreferring to information on other disorders that cannot be displayed onone screen (paragraphs [0062] and [0063] and FIG. 6(E)).

In Patent Literature 1, on the screen of the retrieval result, images ofrepresentative cases of each disorder are sequentially displayed from aposition near to the diagnosis object image to a position distant fromthe diagnosis object case. Therefore, when comparing the diagnosisobject image with an image of a representative case of each disorder,depending on a display position of an image of the representative casethat a radiologist wishes to compare (for example, a disorder G in FIG.6E according to Patent Literature 1), a line-of-sight movement of theradiologist increases because images of other representative case arein-between. In this case, in addition to a physical burden thataccompanies the line-of-sight movement, diagnostic accuracy declines aswell. When a radiologist compares a diagnosis object image with an imageof a representative case, the radiologist performs a detailed comparisonon a large number of items such as a position, a size, a shape, and adistribution of a shadow corresponding to a lesion site in the images.Therefore, when a diagnosis object image and an image of arepresentative case are being displayed separated from each otherinstead of being displayed adjacent to each other, diagnostic accuracyconceivably declines because it is difficult to perform the detailedcomparison described above.

Patent Literature 2 discloses a medical image displaying apparatus thatenables comparative diagnostic interpretation to be readily performed ontomographic image data of a plurality of series of a same patient.Specifically, a reference/comparison object image data display screenincludes a reference tomographic image data display region, a thumbnailimage data display region, and a comparison object image data displayregion. Reference tomographic image data is displayed in the referencetomographic image data display region. In addition, comparison thumbnailimage data is displayed in the thumbnail image data display region. Inthis state, when comparison thumbnail image data that is displayed inthe thumbnail image data display region is dragged and dropped into thecomparison object image data display region, comparison tomographicimage data corresponding to the comparison thumbnail image data isdisplayed in the comparison object image data display region (paragraphs[0046] to and FIG. 7). In this case, comparative diagnosticinterpretation refers to comparative diagnostic interpretation usingimage data obtained by different image diagnostic apparatuses orobtained under different photographic conditions with respect to a samepatient or to comparative diagnostic interpretation using past andlatest image data obtained by a same image diagnostic apparatus withrespect to a same patient.

As described above, since Patent Literature 2 is premised on thecomparison between images of a same patient, Patent Literature 2 doesnot describe comparisons between images of different patients. In imagesof a same patient, positions and the like of shadows corresponding tolesion sites in the images are more or less the same. Therefore,comparative diagnostic interpretation can be performed more efficientlyby performing a detailed comparison using magnified tomographic imagedata instead of performing a comparison using thumbnail images which arereduced tomographic image data. As a result, Patent Literature 2 doesnot disclose a theory in which, when comparing medical images,comparison thumbnail image data and reference tomographic image data aredisplayed adjacent to each other in a thumbnail image stage in order tonarrow down the comparison thumbnail image data.

Non Patent Literature 1 discloses a similar case retrieval system inwhich, due to a function of retrieving a past similar case using alesion image, appropriate information is instantaneously extracted andpresented from clinical knowledge accumulated in PACS described aboveand the like in order to support image diagnosis of a radiologist.Specifically, the present system retrieves case images with features oflesions similar to an examination image and displays a plurality of caseimages in an order of similarity. Subsequently, one reference case imageis selected among the plurality of displayed case images and isdisplayed side by side with the examination image (“2.2 Feature ofPresent System” on page 12 and FIG. 3).

The system disclosed in Non Patent Literature 1 displays the selectedreference case image side by side with an examination image. Therefore,Non Patent Literature 1 does not disclose a theory in which, whencomparing medical images, the examination image and case images that areretrieval results are displayed adjacent to each other in a thumbnailimage stage in order to narrow down the retrieval results.

Based on the considerations described above, the present inventors havearrived at respective aspects of the present disclosure as follows.

An aspect of the present disclosure is a control method of aninformation terminal, which is connected to a medical informationmanagement system that manages medical images that are diagnosticinterpretation object candidates, and which is connected to a caseretrieval system that refers to a medical image database in whichmedical images are registered and retrieves a medical image, andmoreover which includes a display,

one medical image that is a diagnostic interpretation object selectedfrom the diagnostic interpretation object candidates managed by themedical information management system being displayed on the display,

the control method causing a computer of the information terminal to:

sense specification information indicating a region of interest in themedical image;

receive from the case retrieval system one or more similar medicalimages each having a prescribed degree of similarity with a featurequantity of the region of interest indicated by the specificationinformation in accordance with the region of interest;

display the medical image that is managed by the medical informationmanagement system in a first display region of a first display screenthat is displayed on the display and display thumbnail views of aplurality of similar medical images received from the case retrievalsystem in a second display region that differs from the first displayregion of the first display screen, the first display region including afirst display box for displaying the medical image and a second displaybox for displaying a first similar medical image selected from thesimilar medical images displayed in thumbnail views in the seconddisplay region, the first display box and the second display box beingadjacent to each other; and

when sensing an operation for moving the first similar medical imageamong the similar medical images displayed in thumbnail views in thesecond display region to the second display box, display the firstsimilar medical image in the second display box and display the firstsimilar medical image so as to be adjacent to the medical image; wherein

when it is sensed that a first similar medical image selected from theplurality of similar medical images included in the second displayregion is moved to a second display box included in the first displayregion, a second display screen on which the medical image and the firstsimilar medical image are arranged in contrast with each other isdisplayed separately from the first display screen.

According to the present aspect, the medical image that is managed bythe medical information management system and a plurality of similarmedical images received from the case retrieval system are displayedtogether on the first display screen. In other words, images fromdifferent provision sources are displayed integrated on one displayscreen. Accordingly, even images from different provision sources can beprocessed by operations performed on a same display screen.

Therefore, a radiologist can perform subsequent processing of medicalimages of different types that are managed by separate systems as if themedical images are inside a same system.

As a result, for example, even when one system such as the medicalinformation management system and another system that differs from theone system such as the case retrieval system are respectively run, thehassle that is experienced by a radiologist when having to comparedifferent display screens respectively provided by such differentsystems and make a professional judgment can be resolved and, byextension, an improvement in diagnostic accuracy can be achieved.

In addition, with the present aspect, for example, a radiologist narrowsdown a similar medical image to be referred to from a plurality ofsimilar medical images displayed in a thumbnail view in the seconddisplay region. Subsequently, the similar medical image eventuallyselected as a reference image can be moved to the first display regionin which a medical image that is a diagnostic interpretation object isdisplayed.

In doing so, according to the present aspect, for example, a firstdisplay box for displaying the medical image and a second display boxfor displaying a first similar medical image selected from the similarmedical images displayed in the second display region are arranged inthe first display region so as to be adjacent to each other. In otherwords, in the present aspect, a radiologist is prompted to narrow down afinal candidate by a method involving moving the first similar medicalimage to the second display box that is included in the first displayregion.

Accordingly, a similar medical image selected as a final candidate andother similar medical images not selected as the final candidate can bedisplayed separately. Furthermore, the first similar medical image thatis selected as the final candidate is included in the first displayregion which includes a medical image that is the diagnosticinterpretation object. In other words, the first similar medical imageis displayed separated from other similar medical images not selected asthe final candidate in a region that is adjacent to the diagnosticinterpretation object.

Therefore, in addition to displaying the medical image that is thediagnostic interpretation object, the first display region displays thefirst similar medical image selected as the final candidate so as to beadjacent to the medical image and displays the first similar medicalimage and the medical image as a group.

As a result, in a stage prior to making a detailed judgment or, in otherwords, in a thumbnail image stage, for example, a radiologist can beasked to make a simple judgment on whether or not a shadow in the firstsimilar medical image is similar to a shadow in a medical image that isthe diagnostic interpretation object. In this case, for example, whenthe medical image that is the diagnostic interpretation object isdisplayed in the first display region and the first similar medicalimage is displayed in the second display region, even if the radiologistjudges that the shadow in the first similar medical image is similar tothe shadow in the medical image that is the diagnostic interpretationobject, there may be cases where the radiologist judges that the shadowin the first similar medical image is not similar to the shadow in themedical image that is the diagnostic interpretation object if themedical image that is the diagnostic interpretation object and the firstsimilar medical image are displayed in the first display region.

In other words, in the present aspect, since the medical image that isthe diagnostic interpretation object and the first similar medical imageare displayed adjacent to each other in the first display region,selection accuracy when the radiologist selects a similar medical imagethat is a final candidate and therefore must be compared in detail withthe medical image that is the diagnostic interpretation object from thesimilar medical images displayed as a list in the second display regioncan be improved.

For example, when there is a similar medical image that is closer to theshadow in the medical image that is the diagnostic interpretation objectother than the first similar medical image, a judgment can be made toreplace the first similar medical image with the other similar medicalimage in a state prior to making the detailed judgment.

As a result, since selection accuracy of a final candidate in a stageprior to making a detailed judgment (a thumbnail image stage) can beimproved, diagnostic accuracy when subsequently making a detailedjudgment can also be improved. In addition, since a radiologist canselect the similar medical image to be a final candidate in a thumbnailimage stage which involves a smaller amount of information than anoriginal image, the trouble of diagnosing a degree of similarity betweenthe medical image that is the diagnostic interpretation object and asimilar medical image in detail can be eliminated, and the similarmedical image to be a final candidate can be extracted in an efficientmanner.

According to the present aspect, a second display screen on which themedical image and the first similar medical image are arranged incontrast with each other starts up due to an operation involving movingthe first similar medical image to the second display box. In otherwords, an instruction to move the first similar medical image to thesecond display box doubles as an instruction to start up the seconddisplay screen.

Accordingly, a device operation for displaying the second display screencan be omitted and the number of operations can be reduced. Since such areduction in the number of operations reduces the trouble experienced bya radiologist or the time required by the radiologist when performingoperations, the radiologist can further concentrate on making aprofessional judgment accordingly. In other words, a flow of judgmentand continuity of thought by the radiologist can be prevented from beinginterrupted by an interposing device operation. As a result, animprovement in diagnostic accuracy can be promoted.

In addition, according to the present aspect, a second display screenfor diagnosis is started up separately from the first display screen foroperations. Therefore, for example, on the second display screen, bydisplaying a similar medical image at a resolution of an original image,a radiologist can perform a detailed evaluation using the second displayscreen in an effective manner.

Furthermore, in the aspect described above, for example,

when it is sensed that a second similar medical image among theplurality of similar medical images included in the second displayregion is moved to the first display region in a state where the firstsimilar medical image is included in the first display region, the firstsimilar medical image displayed on the second display screen may beswitched to the second similar medical image.

According to the present aspect, when switching the first similarmedical image displayed on the second display screen to the secondsimilar medical image, a step of erasing the first similar medical imagethat is included in the first display region can be omitted. As aresult, since one step involving a mechanical operation can be omittedwhen a radiologist is making a professional diagnosis, diagnosticaccuracy can be improved without interrupting a flow of thought ofdiagnosis.

In addition, in the aspect described above, for example,

the second display box exists in plurality, and

when it is sensed that the second similar medical image has been movedto a second display box in which the first similar medical image isdisplayed so that the second similar medical image overlaps with thesecond display box, the first similar medical image displayed in thesecond display box may be switched to the second similar medical image,and when it is sensed that the second similar medical image has beenmoved to a second display box in which the first similar medical imageis not displayed, the second similar medical image may be displayed inthe second display box.

In this case, when the first similar medical image is displayed in thesecond display box but the first similar medical image is judged not tobe similar to a medical image that is a diagnostic interpretationobject, the first similar medical image may be switched to a secondsimilar medical image by only performing a simple operation of moving adesired second similar medical image from the second display region andcausing the second similar medical image to overlap with the firstsimilar medical image. Therefore, a first similar medical image can beswitched to a second similar medical image without performing anoperation to erase the first similar medical image and work efficiencycan be improved.

In addition, if there is a second display box in which the first similarmedical image is not displayed in the first display region, by movingthe second similar medical image to the second display box, the secondsimilar medical image is displayed in the second display box. Therefore,the second similar medical image can be displayed in the first displayregion while keeping the first similar medical image displayed in thesecond display box. As a result, a plurality of similar medical imagesthat are similar to a medical image that is a diagnostic interpretationobject can be displayed adjacent to each other in the first displayregion and a diagnosis on which of the first and second similar medicalimages is more similar to the medical image that is a diagnosticinterpretation object can be readily made.

Furthermore, in the aspect described above, for example,

the first display screen may include a third display region thatdisplays a similar medical image previously included in the firstdisplay region,

the first display region may include a prescribed number of displayboxes including the first display box and the second display box, and

when the number of similar medical images moved from the second displayregion to the first display region exceeds the prescribed number, thesimilar medical image included in the first display region may be movedto the third display region.

According to the present aspect, even if the number of similar medicalimages moved from the second display region to the first display regionexceeds the prescribed number, a similar medical image that has alreadybeen moved from the second display region to the first display region ismoved to the third display region. In other words, a similar medicalimage that has already been moved from the second display region to thefirst display region is displayed in another display region, namely, thethird display region, which is included in the first display screen, andremains in the first display screen without being erased from the firstdisplay screen.

Therefore, once selected, a similar medical image can be displayeddistinguished from other similar medical images which are included inthe second display region and which have not been selected even if theselected similar medical image has a lower degree of similarity to ashadow in the medical image that is a diagnostic interpretation objectthan similar medical images that are included in the first displayregion.

As a result, by displaying a similar medical image which was onceselected but not kept as a final candidate so as to be distinguishedfrom similar medical images not yet selected, the futility of once againselecting a similar medical image that has already been selected andmoving the similar medical image to the first display region can beeliminated.

In addition, in the aspect described above, for example,

the first display screen may include a third display region thatdisplays a similar medical image previously included or currentlyincluded in the first display region,

the first display region may include a prescribed number of displayboxes including the first display box and the second display box,

when the number of similar medical images moved from the second displayregion to the first display region is equal to or smaller than theprescribed number, the moved similar medical image may be displayed inthe first display region and the third display region, and

when the number of similar medical images moved from the second displayregion to the first display region exceeds the prescribed number, thesimilar medical image included in the first display region may be movedto the third display region.

According to the present aspect, a similar medical image moved from thesecond display region to the first display region is at least displayedin the third display region. As a result, all selected similar medicalimages can be displayed so as to be distinguished from similar medicalimages not yet selected. Therefore, since a radiologist need only checkthe third display region, the futility of once again selecting a similarmedical image that has already been selected and moving the similarmedical image to the first display region can be eliminated.

Furthermore, in the aspect described above, for example,

a display size of a similar medical image in the third display regionmay be set smaller than a display size of a similar medical image in thefirst display region and the second display region.

Since the similar medical images included in the third display regionare similar medical images which had been once selected but not kept asa final candidate or are all selected similar medical images, thesimilar medical images have once been viewed or judged by a radiologist.Therefore, since the similar medical images included in the thirddisplay region remain in the memory of the radiologist to a certaindegree, even if details of the similar medical images are not displayedas large images, a judgment can be made to a certain degree as to whatkind of images the similar medical images are.

On the other hand, a similar medical image not yet selected cannot beappropriately selected in comparison to the medical image that is adiagnostic interpretation object unless displayed as a relatively largeimage.

According to the aspect described above, a display size of a similarmedical image in the third display region is set smaller than a displaysize of a similar medical image in the first display region and thesecond display region. Accordingly, even when the third display regionis included in the first display screen which is limited in terms ofdisplay regions, the first display screen is effectively utilized.Therefore, the first display screen can be effectively utilized bydisplaying similar medical images which had been once selected but notkept as a final candidate and similar medical images not yet selected soas to be distinguished from one another, comparing the similar medicalimages with the medical image that is a diagnostic interpretationobject, and appropriately selecting a similar medical image that issimilar to the medical image that is a diagnostic interpretation object.

In addition, in the aspect described above, for example,

a display arrangement of the second display screen may be the same as adisplay arrangement of a first display region that is included in thefirst display screen.

According to the present aspect, even if the first display screen thatis a display screen for performing operations and the second displayscreen that is a display screen for performing diagnosis are providedseparately, by keeping in mind a layout of a medical image arranged inthe first display region that is included in the first display screen byan operation on the first display screen, a diagnosis can be made usingthe second display screen with the same arrangement.

In addition, positions of shadows corresponding to lesion sites whichare included in similar medical images vary. Therefore, depending on aposition of a shadow included in a similar medical image, aline-of-sight movement may increase when comparing the shadows with ashadow included in a medical image that is a diagnostic interpretationobject. Specifically, as shown in FIG. 73A, when a shadow included in amedical image that is a diagnostic interpretation object exists on aleft side of a right lung as seen on the screen and a shadow included ina similar medical image exists on a right side of a left lung as seen onthe screen, a line-of-sight movement of a radiologist increases if themedical image that is a diagnostic interpretation object is arranged tothe left of the similar medical image on the second display screen. Insuch a case, as shown in FIG. 73B, by arranging the medical image thatis a diagnostic interpretation object to the right of the similarmedical image on the second display screen, the line-of-sight movementof the radiologist can be reduced significantly. As a result, inaddition to reducing a physical burden on the radiologist due to theline-of-sight movement, diagnostic accuracy can be improved. Asdescribed above, there is a need by radiologists to arbitrarily setdisplay positions of a medical image that is a diagnostic interpretationobject and a similar medical image. According to the present aspect,since a radiologist can arbitrarily set a display arrangement of thefirst display region that is included in the first display screen, adisplay arrangement that satisfies the need of the radiologist can berealized on the second display screen used for detailed comparativedisplay.

Furthermore, in the aspect described above, for example,

the display may include a first display and a second display, and

the first display screen may be displayed on the first display and thesecond display screen may be displayed on the second display.

A large number of images are respectively displayed on the first displayscreen and the second display screen. In addition, the displayed imagesrespectively include shadows corresponding to similar lesion sites.Therefore, when a radiologist continues a diagnostic interpretationoperation over an extended period of time, confusion may occur whenviewing the respective display screens as to whether a display screen isthe first display screen to be used to select a similar medical image orthe second display screen to be used to compare a medical image that isa diagnostic interpretation object with the selected similar medicalimage in detail.

According to the present aspect, the first display is used as a displayfor selecting a similar medical image to be comparatively displayed witha medical image that is a diagnostic interpretation object and thesecond display is used as a display for comparing the medical image thatis a diagnostic interpretation object with the selected similar medicalimage in detail. As a result, when a radiologist views the respectivedisplays, the radiologist can be made conscious of whether to select asimilar medical image or to compare a medical image with a selectedsimilar medical image in detail and the confusion described above can beprevented.

In addition, in the aspect described above, for example,

disease name information on a lesion represented in a medical image thatis a diagnostic interpretation object may not be set in additionalinformation of the medical image, and disease name information on alesion represented in each of the plurality of received similar medicalimages may be set in additional information of each of the plurality ofreceived similar medical images.

According to the present aspect, when observing the medical image thatis a diagnostic interpretation object in order to identify a diseasename of a lesion appearing on the medical image that is a diagnosticinterpretation object, diagnostic accuracy can be improved by referringto a similar medical image representing a lesion whose disease name hasalready been identified.

Furthermore, in the aspect described above, for example,

the second display region may include a prescribed number of displayframes, and

images of the prescribed number or less among the plurality of receivedsimilar medical images may be displayed in each of the display frames ina descending order of degrees of similarity with the medical image thatis a diagnostic interpretation object.

According to the present aspect, by displaying the plurality of receivedsimilar medical images in a descending order of degrees of similaritywith the medical image that is a diagnostic interpretation object whencomparing the medical image that is a diagnostic interpretation objectwith the similar medical images in a contrasting manner, the similarmedical images are to be compared with the medical image that is adiagnostic interpretation object in a descending order of degrees ofsimilarity. Therefore, for example, diagnostic accuracy can be improvedby having a disease name of a lesion appearing in the medical image thatis a diagnostic interpretation object identified in an efficient manner.

In addition, in the aspect described above, for example,

the control method may cause the computer of the information terminalto:

transmit information indicating the feature quantity of the region ofinterest to the case retrieval system; and

receive the similar medical image having the prescribed degree ofsimilarity with the feature quantity of the region of interest from thecase retrieval system.

In addition, in the aspect described above, for example,

the control method may cause the computer of the information terminalto:

transmit the one medical image that is a diagnostic interpretationobject and specification information indicating the region of interestto the case retrieval system; and

receive, from the case retrieval system, the similar medical imagehaving the prescribed degree of similarity with the feature quantity ofthe region of interest obtained from the medical image that is adiagnostic interpretation object and the specification information.

In addition, in the aspect described above, for example,

the one medical image that is a diagnostic interpretation object may bea medical image of a lung,

the similar medical image may be a medical image of a lung,

the first display screen may include

first distribution information for selecting a similar medical image inwhich a size of a region corresponding to the region of interest belongsto a prescribed first range, the first range indicating that the size ofthe region corresponding to the region of interest is wider than aprescribed range in a region of the lung, second distributioninformation for selecting a similar medical image in which the size ofthe region corresponding to the region of interest belongs to aprescribed second range, the second range being lower than the firstrange and indicating that the size of the region corresponding to theregion of interest is a part of a region of the lung, and thirddistribution information for selecting a similar medical image in whichthe region corresponding to the region of interest includes a pleura,and

when any one of the first to third items of distribution information isselected, a similar medical image corresponding to the selecteddistribution information may be displayed in the second display region.

According to the present aspect, a plurality of similar medical imagesdisplayed in the second display region may be further sorted based on adistribution type of a lesion region that exists in addition to theregion of interest. Accordingly, for example, a similar medical imagewith a distribution of a lesion region that is similar to a distributiontype of a lesion region that exists in the medical image that is adiagnostic interpretation object in addition to the region of interestcan be efficiently selected from a large number of displayed similarmedical images.

In addition, in the aspect described above, for example,

when selection of the first distribution information is sensed, asimilar medical image corresponding to the first distributioninformation may be displayed in a corresponding display region at aninitial display size,

when selection of the second distribution information is sensed, asimilar medical image corresponding to the second distributioninformation may be magnified and displayed in a corresponding displayregion so as to be centered on the region corresponding to the region ofinterest in the similar medical image corresponding to the seconddistribution information, and

when selection of the third distribution information is sensed, asimilar medical image corresponding to the third distributioninformation may be magnified and displayed in a corresponding displayregion in a state where the pleura is included so as to be centered onthe region corresponding to the region of interest in the similarmedical image corresponding to the third distribution information.

According to the present aspect, when sorting similar medical imagesbased on a distribution type of a region corresponding to the region ofinterest, the similar medical images are not only sorted but alsodisplayed in accordance with the distribution type. Accordingly, aftersorting similar medical images based on a distribution type of a regioncorresponding to the region of interest, the operator is not required toseparately perform a process for magnifying a similar medical image inaccordance with the distribution type, centering the similar medicalimage on a region corresponding to the region of interest, or the like.Therefore, even when a large number of similar medical images are sortedbased on a distribution type of a region corresponding to the region ofinterest, the hassle of repetitively performing a similar operation oneach of the large number of sorted similar medical images can besignificantly reduced. As a result, interruptions of the thought orconcentration of a radiologist that is best focused on making a medicaljudgment by the hassle of performing operations can be significantlyreduced and the thought or concentration of the radiologist can bedirected towards making a medical judgment as it should be. Thus,accuracy of medical judgment can be improved.

In addition, in the aspect described above, for example,

the first distribution information may be information indicating adistribution belonging to a bilateral, a multiple, a diffuse, or ahematogenous category,

the second distribution information may be information indicating adistribution belonging to a segmental or a bronchial category, and

the third distribution information may be information indicating adistribution belonging to a subpleural category.

According to the present aspect, in a case of a distribution belongingto a bilateral, a multiple, a diffuse, or a hematogenous category, asimilar medical image is displayed in an initial display size, in a caseof a distribution belonging to a segmental or a bronchial category, asimilar medical image is magnified and displayed, and in a case of adistribution belonging to a subpleural category, a similar medical imageis magnified and displayed in a state where the pleura is included.

In a case of a distribution belonging to a bilateral, a multiple, adiffuse, or a hematogenous category, it is likely that a lesion site hasspread throughout a lung or that a lesion site has occurred in a widearea of a lung. Therefore, there is a need from a medical perspective todisplay a similar medical image in an initial display size or, in otherwords, without magnification. On the other hand, in a case of adistribution belonging to a segmental or a bronchial category, suchlikelihood is low. Therefore, by magnifying and displaying a similarmedical image when a distribution belonging to a segmental or abronchial category is selected, a step of magnifying and displaying animage can be omitted and the concentration of a radiologist can beprevented from being interrupted. In addition, in a case of adistribution belonging to a subpleural category, a positionalrelationship between the pleura and the lesion site is an importantindicator for diagnosis. Therefore, there is a need from a medicalperspective to magnify to display a similar medical image in a statewhere the pleura is included.

Embodiment

Hereinafter, an embodiment of the present disclosure will be describedwith reference to the drawings. Moreover, in the respective drawings,like symbols are used for like components.

FIG. 1 is an overall configuration diagram of a hospital informationsystem to which an information terminal according to a presentembodiment is applied. As shown in FIG. 1, the hospital informationsystem includes an information terminal 100, a medical informationmanagement system 200, and a case retrieval system 300.

The information terminal 100, the medical information management system200, and the case retrieval system 300 are connected so as to be capableof communicating with each other via a network 400.

The medical information management system 200 and the case retrievalsystem 300 need not necessarily be arranged inside a hospital and may besoftware that runs at a data center or on a private cloud server, apublic cloud server or the like outside of the hospital. When themedical information management system 200 and the case retrieval system300 are installed inside a hospital, a local area network may be adoptedas the network 400. As the local area network, an IEEE 802.3 serieswired LAN, an IEEE 802.11 series wireless LAN, or a network thatcombines the two can be adopted. When the medical information managementsystem 200 and the case retrieval system 300 are realized using serversoutside a hospital, the Internet may be adopted as the network 400.

As the information terminal 100, an information terminal such as apersonal computer or a tablet terminal is adopted. As the medicalinformation management system 200, PACS (Picture Archiving andCommunication Systems), an electronic medical chart system, or the likeis adopted.

FIG. 2 is a block diagram showing configurations of the informationterminal 100, the medical information management system 200, and thecase retrieval system 300. As shown in FIG. 2, the information terminal100 includes a display 101, an operating unit 102, an input control unit103, a display control unit 104, an ROI managing unit 105, a display boxmanaging unit 106, a history information managing unit 107, a diseasename list managing unit 108, a distribution list managing unit 109, acommunication control unit 110, and a box layout managing unit 111.

The display 101 is constituted by a liquid crystal monitor for example,displays a medical image and a medical chart image to be diagnosisobjects and, at the same time, displays a report input image forentering a diagnosis result and the like. While at least one display 101is required, normally, two to three displays 101 are used to performimage diagnosis. In the present embodiment, two displays 101 are used.One of the displays 101 will be referred to as a display 101 a (anexample of the second display) and the other display 101 will bereferred to as a display 101 b (an example of the first display) (referto FIG. 3).

In addition, a display screen of the display 101 a is an example of thesecond display screen and a display screen of the display 101 b is anexample of the first display screen. FIG. 3 is an external view of thetwo displays 101 a and 101 b. In FIG. 3, four medical image viewers aredisplayed in a two-row, two-column arrangement on the display 101 a anda screen of the case retrieval system 300 is displayed on the display101 b. Moreover, when only one display 101 is provided, the firstdisplay screen and the second display screen are displayed by dividingregions on the display screen of the one display 101.

The operating unit 102 includes, for example, a keyboard and a mouse andaccepts various operations input by a user to the information terminal100. For example, the operating unit 102 accepts operations by the useron a medical image and a medical chart image displayed on the display101, operations for inputting a diagnosis result to a report inputscreen, and the like.

Upon sensing an operation by the user on the operating unit 102, theinput control unit 103 interprets a content of the operation andnotifies the operation content to other components. For example, theinput control unit 103 senses a position of a mouse pointer on thedisplay 101 from coordinate data output by a mouse as the operating unit102 and causes the mouse pointer to be displayed on the display 101. Inaddition, if a GUI part (for example, a GUI button) generated by thedisplay control unit 104 is displayed at a display position of the mousepointer upon sensing that the mouse has been clicked, the input controlunit 103 determines that the GUI has been selected by the user andnotifies other components that the GUI has been selected by the user.

The display control unit 104 generates a GUI (Graphical User Interface)of the information terminal 100 and causes the GUI to be displayed onthe display 101.

When performing a similar case retrieval, the ROI managing unit 105generates region of interest information indicating a region of interestthat is set with respect to a retrieval query image (to be describedlater) and stores the region of interest information in a memory, andmanages the region of interest information.

The display box managing unit 106 stores display box managementinformation 4410 (FIG. 44) to be described later in a memory and managesthe display box management information 4410.

The history information managing unit 107 generates history information1701 in which is registered a similar case ID of a similar casedisplayed in a history management region 760 (FIG. 18) to be describedlater and stores the history information 1701 in a memory, and managesthe history information 1701 (FIG. 17).

The disease name list managing unit 108 generates a disease name list(FIG. 35) of similar cases displayed in a case display region 710 (FIG.6) and stores the disease name list in a memory, and manages the diseasename list.

The distribution list managing unit 109 generates a distribution list(FIG. 40) representing a lesion distribution of similar cases displayedin the case display region 710 and stores the distribution list in amemory, and manages the distribution list.

The communication control unit 110 includes, for example, acommunication apparatus for connecting the information terminal 100 tothe network 400 and controls communication between the informationterminal 100 and the medical information management system 200 andcommunication between the information terminal 100 and the caseretrieval system 300. In addition, the communication control unit 110accepts transmission requests of various types of data from other blocksand transmits the data to the medical information management system 200or the case retrieval system 300, and receives data transmitted from themedical information management system 200 or the case retrieval system300 and hands over the data to a corresponding block.

The box layout managing unit 111 generates layout management information4200 (FIG. 42) to be described later and stores the layout managementinformation 4200 in a memory, and manages the layout managementinformation 4200.

As shown in FIG. 2, the medical information management system 200includes a patient information accumulating unit 201, a patientinformation managing unit 202, a medical image data accumulating unit203, a medical image data managing unit 204, a diagnostic reportmanaging unit 205, and a communication control unit 206.

The patient information accumulating unit 201 accumulates patientinformation 1000 (FIG. 22) in which personal information of a patientsuch as gender and age, clinical information of the patient such asmedical history, and examination information of the patient such as ablood test are registered.

With respect to the patient information 1000 (FIG. 22) accumulated inthe patient information accumulating unit 201, the patient informationmanaging unit 202 executes a process for registering data input by theuser and updating the patient information 1000, a process for outputtingthe patient information 1000 to the display control unit 104, and thelike, and manages the patient information 1000. The medical image dataaccumulating unit 203 accumulates medical image data that representsexamination images of a patient.

The medical image data managing unit 204 accumulates medical image datain the medical image data accumulating unit 203 and manages the medicalimage data.

The diagnostic report managing unit 205 manages a diagnostic report 3000(FIG. 25) that represents a diagnosis result by a radiologist withrespect to respective examinations performed on a patient.

The communication control unit 206 includes, for example, acommunication apparatus for connecting the medical informationmanagement system 200 to the network 400, accepts transmission requestsof various types of data from other blocks and transmits the data to theinformation terminal 100 or the case retrieval system 300, and receivesdata transmitted from the information terminal 100 or the case retrievalsystem 300 and hands over the data to a corresponding block.

As shown in FIG. 2, the case retrieval system 300 includes a similarcase data accumulating unit 301, an image feature extracting unit 302, asimilar case retrieving unit 303, and a communication control unit 304.

The similar case data accumulating unit 301 accumulates, in advance,similar case data 4000 (FIG. 26) in which image features extracted froma large number of similar cases selected as object data of similar caseretrieval among similar cases managed by the medical informationmanagement system 200, thumbnail images generated from the large numberof similar cases, and the like are registered.

The image feature extracting unit 302 extracts an image feature inregion of interest information of a retrieval query image transmittedfrom the communication control unit 110 of the information terminal 100.In this case, the region of interest information is an example of thespecification information indicating the region of interest.

The similar case retrieving unit 303 generates a similar case retrievalresult by respectively comparing the image feature extracted by theimage feature extracting unit 302 and image features of one or moresimilar cases accumulated in the similar case data accumulating unit301.

The communication control unit 304 includes, for example, acommunication apparatus for connecting the case retrieval system 300 tothe network 400, accepts transmission requests of various types of datafrom other blocks and transmits the data to the information terminal 100or the medical information management system 200, and receives datatransmitted from the information terminal 100 or the medical informationmanagement system 200 and hands over the data to a corresponding block.

FIG. 4 is a diagram showing a configuration example of an implementationof the information terminal 100. As shown in FIG. 4, the informationterminal 100 includes an application 501, an OS (Operating System) 502,a memory 503, and other hardware not shown.

The application 501 is application software for causing a personalcomputer or a tablet terminal to function as the information terminal100 and is executed by a processor of the information terminal 100. Theinformation terminal 100 may implement the application 501 by readingthe application 501 from a computer-readable recording medium or mayimplement the application 501 by downloading the application 501 from anetwork.

In this case, the application 501 includes a medical informationmanagement application and a similar case retrieval application. Themedical information management application is an application for causingthe information terminal 100 to work in cooperation with the medicalinformation management system 200 and the similar case retrievalapplication is an application for causing the information terminal 100to work in cooperation with the case retrieval system 300. In addition,both applications transmit and receive data to and from each other andintegrate services provided by the medical information management system200 and the case retrieval system 300 in the information terminal 100.

The OS 502 is basic software of the information terminal 100 and isexecuted by a processor of the information terminal 100. The memory 503is constituted by a storage apparatus such as a RAM or a ROM included inthe information terminal 100 and stores a group of data included in theapplication 501.

As the processor of the information terminal 100 executes theapplication 501, functions of the input control unit 103, the displaycontrol unit 104, the ROI managing unit 105, the display box managingunit 106, the history information managing unit 107, the disease namelist managing unit 108, the distribution list managing unit 109, thecommunication control unit 110, and the box layout managing unit 111,which are shown in FIG. 2, are realized.

However, in the present embodiment, the information terminal 100 may beonly mounted with the application 501, mounted with the application 501and the OS 502, mounted with the application 501, the OS 502, and thememory 503, or mounted with the application 501, the OS 502, the memory503, and other hardware not illustrated. The information terminal 100according to the present embodiment can be realized by any of theimplementations.

FIG. 5 is a diagram showing an example of a basic screen K1 that isdisplayed on a display 101 a immediately after starting the similar caseretrieval application on the information terminal 100. The basic screenK1 shown in FIG. 5 is constituted by four medical image viewers 610 to640. A medical image is normally recorded in a DICOM (Digital Imagingand Communication in Medicine) format and the medical image viewers 610to 640 are viewers capable of handling DICOM. A medical image handled inthe present embodiment is assumed to be a chest CT image that isconstituted by a large number of tomographic images (hereinafter,referred to as slice images) in the DICOM format. However, this issimply an example and CT images of another site (for example, the head,the abdomen, a leg, and an arm) may be adopted instead.

In a chest CT image displayed on the medical image viewers 610 to 640,slice images are switched by an operation of a mouse or a keyboard. Inthis case, the slice images constituting a chest CT image are arrangedin an order from, for example, the neck toward the abdomen.

For example, when a mouse pointer is positioned on the medical imageviewer 610 and a rotation of a mouse wheel is sensed by the inputcontrol unit 103, the display control unit 104 switches a slice imagethat is displayed on the medical image viewer 610 in accordance with anamount of the sensed rotation. For example, when the mouse wheel isrotated by one click toward the rear of the mouse on the medical imageviewer 610, the display control unit 104 switches a slice image beingdisplayed to a slice image at a next slice position. On the other hand,for example, when the mouse wheel is rotated by one click toward thefront of the mouse on the medical image viewer 610, the display controlunit 104 switches a slice image being displayed to a slice image at animmediately previous slice position. Therefore, a user such as aradiologist switches slice images displayed on the medical image viewer610 as appropriate by rotating the mouse wheel forward or backward toretrieve a desired slice image.

Moreover, as the medical image, an MRI (Magnetic Resonance Imaging)image or a plain radiographic image may be adopted instead of a chest CTimage. In addition, while the number of medical image viewers is set tofour in the example shown in FIG. 5, this is simply an example andanother number such as six and eight may be adopted instead. While anincrease in the number of medical image viewers increases the number ofimages that can be simultaneously compared, a display area per imagedecreases. Therefore, for the number of medical image viewers, aconfiguration that can be appropriately modified in accordance with adisplay size of the display 101 a may be adopted. In this case, it isassumed that the number of medical image viewers can be changed at willby a user or an administrator.

Before the similar case retrieval application is started, a slice imageof a chest CT image of a patient is displayed across an entire region ofthe display 101 a. In addition, in this state, as the similar caseretrieval application is started by a user such as diagnosticinterpreter, the slice image that had been displayed across the entireregion of the display 101 a is displayed on the medical image viewer610.

In other words, when the user starts the similar case retrievalapplication, a retrieval query image that had been displayed across theentire region of the display 101 a is initially displayed on the medicalimage viewer 610. Moreover, the display control unit 104 may display aregion of interest (ROI) that is an object of similar case retrieval soas to overlap with the retrieval query image. A retrieval query image isan example of the medical image that is the diagnostic interpretationobject.

In FIG. 5, while no images are displayed on the other medical imageviewers 620 to 640, when there are a plurality of examination images ofa patient that are diagnosis objects and a plurality of examinationimages are displayed on the display 101 a before the similar caseretrieval application is started, the display control unit 104 maydisplay the plurality of examination images without modification on themedical image viewers 620 to 640.

FIG. 6 is a diagram showing an example of a basic screen K2 that isdisplayed on a display 101 b immediately after starting the similar caseretrieval application on the information terminal 100. The basic screenK2 shown in FIG. 6 includes a case display region 710, a layout region720, a disease name list display region 730, and a distribution listdisplay region 750. Moreover, the layout region 720 is an example of thefirst display region and the case display region 710 is an example ofthe second display region.

The case display region 710 is a region for displaying thumbnail imagesof similar cases that are similar to the retrieval query image in anorder of degrees of similarity. In this case, the thumbnail image of thesimilar case is an example of the similar medical image.

Since a large number of similar cases are displayed in the case displayregion 710, performing a conversion of resolution or a pixel value inthe case display region 710 results in an extended processing time.Therefore, thumbnail images are created in advance from original sliceimages and saved in the case retrieval system 300.

Hereinafter, additional explanation of a conversion of resolution or apixel value will be provided. While the resolution of an original sliceimage is 512×512 pixels, since the resolution of a thumbnail image ismuch lower, resolution conversion must be performed. In considerationthereof, a thumbnail image is generated by performing a low resolutionprocess and a gradation conversion process on an original slice image.

For example, a gradation conversion process is performed as follows. Ina slice image acquired by CT, each pixel value (CT value) takes a valueof 2000 grayscale ranging from −1000 to +1000 (in HU: Hounsfield Units)and cannot be displayed as-is on an ordinary 8-bit grayscale display. Inaddition, even if the image can be displayed, it is difficult for aperson to distinguish a pulmonary emphysema region (CT value: −1000 HU),a normal lung field tissue (CT value: about −900 HU), a ground-glassregion (CT value: −800 HU), a soft tissue (CT value: −100 to −50 HU),water (CT value: 0 HU), and bone (CT value: 1000 HU) among 2000grayscale with the naked eye.

Therefore, normally, with a slice image, a window level and a windowwidth are set with respect to each pixel value, the pixel value isreconstructed into an 8-bit pixel value, and the slice image isdisplayed on the display. In this case, a window level represents a CTvalue at a center of a window and a window width represents a verticalwidth of the center of the window.

For example, when a DICOM image is reconstructed in a lung windowsetting, the window level is set to −550 to −800 and the window width isset to 1000 to 1600. Therefore, a thumbnail image is also generated byreducing a pixel value to 8 bits from an original slice image with theprocess described above.

Moreover, the thumbnail image displayed in the case display region 710is a thumbnail image representing a similar case whose distance from afeature vector of a diagnosis object case is equal to or less than apredetermined threshold. In this case, for example, a Euclidean distanceis used as the distance. Alternatively, a different distance scale suchas a city block distance may be adopted as the distance. The closer thedistance between two comparison object images, the more similar. Inaddition, as the feature vector, a feature vector obtained not from athumbnail image but from a slice image that is an original image isadopted.

FIG. 7 is an extracted view showing a display region of one similar casethat is displayed in the case display region 710. A thumbnail image isdisplayed in the display region of the similar case and a definitivelydiagnosed disease name display region 711 and a distance display region712 are arranged below the thumbnail image. A definitively diagnoseddisease name of a similar case that is an object is displayed in thedefinitively diagnosed disease name display region 711. A definitivelydiagnosed disease name refers to a disease name representing a finalizeddiagnosis of a similar case that is an object. The distance displayregion 712 displays a distance between a feature vector of a slice imageof a similar case that is an object and a feature vector of a retrievalquery image. In the example shown in FIG. 7, since “nontuberculousmycobacteria” is displayed in the definitively diagnosed disease namedisplay region 711, the thumbnail image is a thumbnail image of asimilar case that has been definitively diagnosed as “nontuberculousmycobacteria”. In addition, since “0.05” is displayed in the distancedisplay region 712, it is shown that a distance between the slice imageof the similar case and the retrieval query image is “0.05”.

Returning now to FIG. 6, a number of retrieved results display region713 is arranged in, for example, a top left part of the basic screen K2.The number of retrieved results display region 713 displays the numberof similar cases which are similar to the diagnosis object case asacquired from the case retrieval system 300 as a result of a retrievingprocess.

Moreover, when the number of similar cases is significantly large, thecase display region 710 cannot display all similar cases at the sametime. In consideration thereof, a scroll bar 715 that is elongated in avertical direction is provided on the right side of the case displayregion 710, for example. The display control unit 104 displays athumbnail image displayed in the case display region 710 by scrollingthe thumbnail image in a vertical direction in accordance with an amountof movement of the scroll bar 715. Accordingly, the user can display asimilar case previously in a non-displayed state in the case displayregion 710 and observe the similar case.

Moreover, the scroll bar 715 may be elongated in a horizontal direction.In this case, the display control unit 104 may display a thumbnail imagedisplayed in the case display region 710 by scrolling the thumbnailimage in a horizontal direction in accordance with an amount of movementof the scroll bar 715. Alternatively, when a direction key of thekeyboard is pressed in a state where the mouse pointer is positioned onthe case display region 710, the display control unit 104 may display athumbnail image displayed in the case display region 710 by scrollingthe thumbnail image in a direction of the pressed key while the key isbeing pressed.

Moreover, while the information terminal 100 is configured to acquire athumbnail image whose distance from a retrieval query image is equal toor less than a predetermined threshold from the case retrieval system300, this is simply an example. For example, the information terminal100 may always acquire a constant number of thumbnail images from thecase retrieval system 300 in a descending order of degrees ofsimilarity. Alternatively, the information terminal 100 may acquirethumbnail images from the case retrieval system 300 so as to alwaysinclude a constant number of thumbnail images representing a givendefinitively diagnosed disease name.

Moreover, as a method of displaying thumbnail images in the case displayregion 710, a display method can be adopted which involves displaying athumbnail image whose distance from a retrieval query image is shortestat a left end of an uppermost row, displaying thumbnail images so thatdistances sequentially increases rightward, and once reaching a rightend of the same row, displaying a thumbnail image with a next longerdistance at a left end of a second-from-top row, for example. In otherwords, a display method can be adopted which involves displayingthumbnail images in an ascending order of distances so as to meanderfrom top left to bottom right in the case display region 710.

Obviously, the present embodiment may adopt other display methods. Forexample, a display method can be adopted which involves displaying athumbnail image whose distance is shortest at an upper end of a leftmostcolumn, displaying thumbnail images so that distances sequentiallyincreases downward, and once reaching a lower end of the same column,displaying a thumbnail image with a next longer distance at an upper endof a second-from-left column. In addition, a configuration may beadopted in which the user can switch among the plurality of displaymethods.

Furthermore, while distance is adopted as a degree of similarity in theexample described above, any indicator such as cosine similarity may beadopted as long as the indicator represents a degree of similaritybetween images. When cosine similarity is adopted, the degree ofsimilarity between two images that are comparison objects increases asthe value approaches 1.

Moreover, while details will be provided later, similar cases displayedin the case display region 710 can be narrowed down by a disease namedisplayed in the disease name list display region 730 or by a lesiondistribution displayed in the distribution list display region 750. Acurrently set narrowing condition of similar cases is displayed in adisplay condition display region 714. Since the example shown in FIG. 6shows a state immediately after similar case retrieval and the similarcases have not been narrowed down in any way, “all disorders” aredisplayed in the display condition display region 714.

The layout region 720 is arranged in a bottom left part of the basicscreen K2 shown in FIG. 6, for example. In addition, the layout region720 is used to display an image which the user wishes to observe indetail among the similar case thumbnail images displayed in the casedisplay region 710 on a medical image viewer of the display 101 a. Asshown in FIG. 5, four medical image viewers 610 to 640 are arranged intwo rows and two columns on the display 101 a. In addition, four displayboxes 721 to 724 exist in two rows and two columns in the layout region720. In this manner, the number and arrangement of the medical imageviewers 610 to 640 displayed on the display 101 a and the number andarrangement of the display boxes 721 to 724 in the layout region 720 arematched with each other. As shown in FIG. 5, in conformance of aretrieval query image displayed in the medical image viewer 610, athumbnail image of the retrieval query image is initially displayed inthe display box 721. Moreover, the display box 721 that displays thethumbnail image of the retrieval query image is an example of the firstdisplay box.

The other display boxes 722 to 724 display thumbnail images of similarcases in conjunction with the medical image viewers 620 to 640.Specifically, when the input control unit 103 senses one of thethumbnail images displayed in the case display region 710 being draggedand dropped in any one of the display boxes 722 to 724, the displaycontrol unit 104 displays the one thumbnail image in the display boxand, at the same time, displays a slice image corresponding to thethumbnail image on the medical image viewer corresponding to the displaybox. In this manner, the medical image viewers 610 to 640 correspondone-to-one with the display boxes 721 to 724.

In the example shown in FIG. 6, since the display boxes 722 to 724 areempty, the medical image viewers 620 to 640 shown in FIG. 5 are alsoblank. Moreover, the display boxes 722 to 724 that display similar casesare examples of the second display box.

By dragging and dropping using a mouse, the user moves a thumbnail imagethat the user wishes to observe in detail from the case display region710 to the layout region 720. For example, assuming that the user hasmoved a thumbnail image to the display box 722, a slice imagecorresponding to the thumbnail image is displayed on the medical imageviewer 620 corresponding to the display box 722. In a similar manner,assuming that the user has moved a thumbnail image to the display box723, a slice image corresponding to the thumbnail image is displayed onthe medical image viewer 630 corresponding to the display box 723. Inother words, when a thumbnail image is moved to any display box amongthe display boxes 721 to 724, a thumbnail image of a similar case isdisplayed adjacent to a thumbnail image of a retrieval query image.Therefore, the user can compare a diagnosis object case with a similarcase on a thumbnail image level and can promptly determine a degree ofsimilarity between both cases. In other words, since an amount ofinformation in a thumbnail image is smaller than that of a slice image,the user can make a rough estimate as to how similar the diagnosisobject case and the similar case arranged adjacent to each other in thelayout region 720 are to each other. Therefore, the user can efficientlynarrow down a final candidate of a similar case which needs to becompared in detail at a slice image level with the diagnosis object casefrom the large number of similar cases displayed in the case displayregion 710.

In a similar manner, the display 101 a also displays slice images of theretrieval query image and a similar case in the same arrangementrelationship as in the layout region 720. Therefore, once an operationfor narrowing down a final candidate of a similar case in the layoutregion 720 is finished, the diagnosis object case and a similar casethat has been narrowed down as a final candidate are displayed on aslice image level in the display 101 a without having to input anyoperation. As a result, the user can make a smooth transition to a nextoperation step that is to diagnostically interpret a diagnosis objectand a similar case that is a final candidate in detail.

The disease name list display region 730 to which a heading reading“disease name list” is attached is arranged in an upper part of a leftside of the basic screen K2 shown in FIG. 6. Definitively diagnoseddisease names of all similar cases acquired as a similar case retrievalresult are displayed in the disease name list display region 730. Aftera diagnosis is made and a definitively diagnosed disease name isassigned, a diagnosis object case is accumulated as a similar case inthe case retrieval system 300. Therefore, a definitively diagnoseddisease name assigned by a diagnosis is assigned in advance to eachsimilar case.

FIG. 8 is an enlarged view of the disease name list display, region 730.In FIG. 8. definitively diagnosed disease names are displayed dividedinto broadly categorized disease names (731, 734, 737, 741, and 744) andfinely categorized disease names (732, 733, 735, 736, 738, 739, 740,742, 743, and 745). In the example shown in FIG. 8, mycosis 731,neoplastic 734, nonneoplastic 737, mycobacteriosis 741, and other 744are displayed as broadly categorized disease names.

In addition, in the example shown in FIG. 8, aspergillosis 732 andcryptococcosis 733 are displayed as finely categorized disease name ofmycosis 731. Furthermore, lung cancer 735 and metastatic lung cancer 736are displayed as finely categorized disease names of neoplastic 734.Moreover, lung abscess 738, sarcoidosis 739, and septic emboli 740 aredisplayed as finely categorized disease names of nonneoplastic 737. Inaddition, nontuberculous mycobacteria (NTM) 742 and tuberculosis 743 aredisplayed as finely categorized disease names of mycobacteriosis 741.Furthermore, bronchiectasis 745 is displayed as a finely categorizeddisease name of other 744.

In addition, the number of cases corresponding to a disease name isdisplayed besides broadly categorized disease names and finelycategorized disease names. By selecting an arbitrary row of a broadlycategorized disease name or a finely categorized disease name in thedisease name list display region 730, the user can narrow down a similarcase to be displayed in the case display region 710. While 62 similarcases including various disorders are set as display objects in a stateimmediately following similar case retrieval as shown in FIG. 6, whenthe row of mycosis 731 in FIG. 8 is clicked using a mouse, the displaycontrol unit 104 only displays similar cases of mycosis in the casedisplay region 710 as shown in FIG. 9. Furthermore, when the row ofmetastatic lung cancer 736 in FIG. 8 is clicked using a mouse, thedisplay control unit 104 only displays similar cases of metastatic lungcancer in the case display region 710 as shown in FIG. 10.

At this point, the display control unit 104 displays narrowed-downdisease names in the display condition display region 714 so as to showwhat kind of narrowing condition applies to the similar cases currentlydisplayed in the case display region 710. FIG. 9 is a diagram showingthe basic screen K2 when similar cases are narrowed down by “mycosis”.FIG. 10 is a diagram showing the basic screen K2 when similar cases arenarrowed down by “metastatic lung cancer”.

In the example shown in FIG. 9, since similar cases are narrowed down by“mycosis”, “mycosis” is displayed in the display condition displayregion 714. In the example shown in FIG. 10, since similar cases arenarrowed down by “metastatic lung cancer”, “metastatic lung cancer” isdisplayed in the display condition display region 714.

In addition, at this point, the display control unit 104 shows thenumber of similar cases currently displayed in the case display region710 by displaying the number in the number of retrieved results displayregion 713. In the example shown in FIG. 9, since there are 14 similarcases corresponding to “mycosis”, “14” is displayed in the number ofretrieved results display region 713. In the example shown in FIG. 10,since there are 3 similar cases corresponding to “metastatic lungcancer”, “3” is displayed in the number of retrieved results displayregion 713.

Due to this function, only similar cases with disease names that areassumed to be objects of image diagnosis by a radiologist are displayedin the case display region 710 and the radiologist can readily checkwhether or not the diagnosis object case is consistent with the assumeddisease names.

The distribution list display region 750 to which a heading reading“lesion distribution” is attached is arranged in a middle part of theleft side of the basic screen K2 shown in FIG. 6. Types of lesiondistributions of all similar cases acquired from the case retrievalsystem 300 as a result of similar case retrieval are displayed in thedistribution list display region 750.

FIG. 11 is an enlarged view of the distribution list display region 750.In the example shown in FIG. 11, names of seven lesion distributions aredisplayed and a check mark is arranged to the left of the name of eachlesion distribution. In the example shown in FIG. 11, diffuse 751,segmental 752, bronchial 753, bilateral 754, multiple 755, subpleural756, and hematogenous 757 are displayed as lesion distributions.

These lesion distributions are defined in advance and a distributionflag value (applicable: 1, not applicable: 0) indicating whether or nota similar case corresponds to any of diffuse 751 to hematogenous 757 isassigned to each similar case. Similar cases include those in which alldistribution flag values are set to not applicable (: 0) and those inwhich a plurality of all distribution flag values are set to applicable(: 1).

The case retrieval system 300 according to the present embodimentretrieves a similar case having a region of interest that is similar toa region of interest set by the user in a slice image of a diagnosisobject case. There may exist lesions other than the slice image to whicha region of interest is set by the user. In addition, there may be caseswhere, after retrieving a similar case based on the slice image to whicha region of interest is set, the user wishes to compare a slice imageother than the slice image with the retrieved similar case. In such acase, the user inputs a slice feeding operation on the medical imageviewer 610 to cause the medical image viewer 610 to display anotherslice image and performs an operation for comparing the slice image withthe retrieved similar case. In this case, if only similar cases relatedto a lesion of interest among all retrieved similar cases are displayedin the case display region 710, an operation of extracting a slice imagehaving a desired lesion from slice images other than the slice image towhich a region of interest is set can be performed smoothly. Inconsideration thereof, in the present embodiment, a function fornarrowing down retrieved similar cases by a desired lesion distributionis provided to enable this operation to be performed in a smooth manner.

In the present embodiment, as lesion distributions in a lung fieldregion, the lesion distributions represented by diffuse 751 tohematogenous 757 shown in FIG. 11 are adopted. In addition, as shown inFIG. 11, with respect to check boxes and disease name distributions, thedisplay control unit 104 displays lesion distributions that can benarrowed down in an active state and displays lesion distributions thatcannot be narrowed down in an inactive state. In this case, a state inwhich brightness is higher than the inactive state is adopted as theactive state and a state in which brightness is lower than the activestate is adopted as the inactive state.

In the example shown in FIG. 11, diffuse 751, bronchial 753 to multiple755, and hematogenous 757 are displayed in the active state andsegmental 752 and subpleural 756 are displayed in the inactive state.This is because, among all similar cases acquired by a similar caseretrieval, the distribution flag values of diffuse 751, bronchial 753 tomultiple 755, and hematogenous 757 are currently set to 1 (applicable)in at least one of the similar cases while the distribution flag valuesof segmental 752 and subpleural 756 are currently set to 0 (notapplicable) in all of the acquired similar cases.

When the input control unit 103 senses that a check mark has been inputto one or more check boxes among the check boxes in the active state,the display control unit 104 displays only similar cases correspondingto lesion conditions for which a check mark had been input in the casedisplay region 710.

Moreover, for segmental 752 and subpleural 756, the distribution flagvalue is set to 0 (not applicable) in all of the similar cases acquiredas a retrieval result. Therefore, when a configuration that enables acheck mark to be input for segmental 752 or subpleural 756 is adoptedand a check mark is input for these lesion distributions, no similarcase is to be displayed in the case display region 710. As a result,inputting a check mark becomes meaningless. In consideration thereof, inthe present embodiment, in order to avoid such circumstances, a lesiondistribution for which the distribution flag value is set to 0 (notapplicable) in all of the similar cases acquired as a retrieval resultis displayed in the inactive state.

FIG. 12 is a diagram showing the distribution list display region 750 inwhich a check mark is input. FIG. 13 is a diagram showing the basicscreen K2 having been narrowed down by a bronchial lesion distribution.When a check mark is input to the check box of bronchial 753 as shown inFIG. 12, the display control unit 104 displays only similar cases with abronchial lesion distribution in the case display region 710 as shown inFIG. 13. In this example, there are 17 similar cases with a bronchiallesion distribution. Therefore, the display control unit 104 displays“17” in the number of retrieved results display region 713. In addition,the display control unit 104 displays a disease name that is a displayobject and “bronchial” that is the name of the lesion distribution inthe display condition display region 714. In the example shown in FIG.13, since similar cases have not been narrowed down by a disease namelisted in the disease name list display region 730, the displaycondition display region 714 displays “all disorders”.

FIG. 14 is a diagram showing the distribution list display region 750 inwhich a plurality of check marks are input. FIG. 15 is a diagram showingthe basic screen K2 having been narrowed down by a plurality of lesiondistributions. In the example shown in FIG. 14, check marks are inputfor diffuse 751 and hematogenous 757. Therefore, the display controlunit 104 displays similar cases with diffuse and hematogenous lesiondistributions in the case display region 710 as shown in FIG. 15. Inthis example, there are 11 similar cases with diffuse and hematogenouslesion distributions. Therefore, the display control unit 104 displays“11” in the number of retrieved results display region 713. In addition,the display control unit 104 displays a disease name that is a displayobject (in this case, “all disorders” since similar cases have not beennarrowed down by a disease name) and “diffuse and hematogenous” that arethe names of the lesion distributions in the display condition displayregion 714.

Next, the history management region 760 that is not displayed on thebasic screen K2 shown in FIG. 6 will be described. FIG. 18 is a diagramshowing the basic screen K2 displaying the history management region760. The history management region 760 is an example of the thirddisplay region. When the input control unit 103 senses an operation forpositioning the mouse cursor near a lowermost part of the case displayregion 710 or for pressing a key assigned in advance, the displaycontrol unit 104 displays the history management region 760 explicitlylabeled “history” at a left end thereof so as to overlap with the basicscreen K2 as shown in FIG. 18. The history management region 760 is arectangular strip-shaped display region that is displayed in a lowerpart of the basic screen K2 and a horizontal width thereof isapproximately the same as a horizontal width of the case display region710. In addition, in the history management region 760, thumbnail imagesmoved to the layout region 720 among the thumbnail images of similarcases displayed in the case display region 710 and thumbnail imagesdirectly moved to the history management region 760 are arranged fromleft to right as history.

Moreover, the history management region 760 is displayed in a lower partof the basic screen K2 because among the similar cases displayed in thecase display region 710, the higher a similar case is in the casedisplay region 710, the more similar the similar case is to thediagnosis object case and therefore the more important. Therefore, asituation where important similar cases become hidden can be avoidedeven when the history management region 670 is displayed. Moreover, thehistory management region 760 other than a region in which thumbnailimages are displayed is translucently displayed. Therefore, thumbnailimages in the case display region 710 that is hidden behind the historymanagement region 760 are prevented from being completely hidden.

In this case, the display control unit 104 displays thumbnail images tobe displayed in the history management region 760 in a smaller size thanthe thumbnail images to be displayed in the case display region 710. Thethumbnail images displayed in the history management region 760 areimages which have already been displayed once in the layout region 720and the case display region 710 and on the medical image viewers 610 to640 and which have already been confirmed once by the user. Therefore,displaying the thumbnail images in a smaller size than the thumbnailimages displayed in the case display region 710 does not pose a problem.In consideration thereof, in the present embodiment, the thumbnailimages displayed in the history management region 760 are set smallerthan the thumbnail images displayed in the case display region 710 andthe layout region 720. Accordingly, as many thumbnail images as possiblecan be displayed in the history management region 760 that has a limiteddisplay space.

Moreover, since the history management region 760 is a display regionthat is elongated in a horizontal direction, when there are a largenumber of thumbnail images moved to the layout region 720 and thehistory management region 760, all of the moved thumbnail images cannotbe displayed.

In consideration thereof, in the present embodiment, when the historymanagement region 760 becomes full of thumbnail images, the displaycontrol unit 104 expands the display space of the history managementregion 760 to two rows as shown in FIG. 19 so that all of the movedthumbnail images can be displayed. FIG. 19 is a diagram showing thebasic screen K2 displaying the history management region 760 in whichthe display space is expanded to two rows. In the example shown in FIG.19, first to seventh thumbnail images in the order of movement to thelayout region 720 and the history management region 760 are displayed ina first row and three thumbnail images moved eighth and thereafter inthe order of movement are displayed in a second row.

Moreover, the display control unit 104 may sequentially expand thenumber of rows of the history management region 760 such as by expandingthe number of rows of the history management region 760 to three rowswhen the history management region 760 with a display space expanded totwo rows becomes full of thumbnail images, expanding the number of rowsof the history management region 760 to four rows when the historymanagement region 760 after expansion becomes full of thumbnail images,and so on.

In addition, as shown in FIG. 20, the display control unit 104 maydisplay a scroll bar 761 that is elongated in a horizontal direction ina lower part of the history management region 760 instead of increasingthe number of rows of the history management region 760. FIG. 20 is adiagram showing the history management region 760 in which the scrollbar 761 is displayed. In this case, when the scroll bar 761 is movedhorizontally, the display control unit 104 may scroll thumbnail imagesdisplayed in the history management region 760 in the horizontaldirection in accordance with an amount of movement of the scroll bar761. Accordingly, thumbnail images that cannot be displayed in a displayspace corresponding to one row can be displayed in the historymanagement region 760 that only has a display space corresponding to onerow.

Moreover, in the present embodiment, while a mode is adopted in whichthe history management region 760 is hidden in an initial state andappears when necessary, the history management region 760 may bedisplayed in an initial state as shown in FIG. 21. FIG. 21 is a diagramshowing a basic screen in a case where a mode that displays the historymanagement region 760 from an initial state is adopted.

In the example shown in FIG. 21, in order to display as many thumbnailimages in the history management region 760 as possible, the thumbnailimages to be displayed in the history management region 760 are set evensmaller than a case where the mode shown in FIG. 18 is adopted. In thiscase, when the mode shown in FIG. 21 is adopted, the display controlunit 104 may expand the history management region 760 shown in FIG. 21so as to assume a same size as the history management region 760 shownin FIG. 16 as the mouse cursor is brought close to the historymanagement region 760 that is constantly displayed.

Moreover, the thumbnail images displayed in the history managementregion 760 are registered in history information 1701 (refer to FIG. 17)that is managed by the history information managing unit 107. Therefore,the display control unit 104 identifies a thumbnail image displayed inthe history management region 760 by referring to history information.Hereinafter, a registration process to history information 1701 will bedescribed. FIG. 16 is a flow chart showing a registration process tohistory information 1701. First, when the input control unit 103 sensesan operation where a thumbnail image displayed in the case displayregion 710 is dragged and dropped (YES in S300), a judgment is made onwhether or not a position at which the thumbnail image is dropped is inthe layout region 720 (S310). On the other hand, if a drag-and-dropoperation is not detected, (NO in S300), the process of S300 isrepeated.

When a position where the thumbnail image is dropped is inside thelayout region 720 (YES in S310), the process advances to S330. On theother hand, when the position where the thumbnail image is dropped isoutside the layout region 720 (NO in S310), the process advances toS320.

In S320, the input control unit 103 judges whether or not the droppedposition is inside the history management region 760, When the droppedposition is inside the history management region 760 (YES in S320), theprocess advances to S330. On the other hand, when the dropped positionis outside the history management region 760 (NO in S320), the processreturns to S300.

In S330, the history information managing unit 107 judges whether or nota similar case ID of the dropped thumbnail image is already included inthe history information 1701. FIG. 17 is a diagram showing a dataconfiguration of the history information 1701. The history information1701 is information for managing a thumbnail image to be displayed inthe history management region 760. The history information 1701 includesa “history ID” field and a “similar case ID” field. The “history ID” isinformation indicating an order of registration in which a similar casehad been registered in the history information 1701. In this case, asthe “history ID”, a natural number that is incremented by 1 every time anew similar case is registered in the history information 1701 isadopted. The “similar case ID” is an identifier for uniquely identifyinga similar case. In the example shown in FIG. 17, a symbol stringconstituted by “SIM” followed by a numerical value is adopted. Moreover,the “similar case ID” is associated with thumbnail image data 4500 inthe similar case data 4000 shown in FIG. 26. Therefore, if a similarcase ID is known, a corresponding thumbnail image can be identified.

When the similar case of the dropped thumbnail image is included in thehistory information 1701 (YES in S330), since a corresponding similarcase need not be registered in the history information 1701, the processreturns to S300. On the other hand, when the similar case of the droppedthumbnail image is not included in the history information 1701 (NO inS330), the history information managing unit 107 adds the similar caseID of the dropped thumbnail image to the history information 1701(S340). In this case, the history information managing unit 107 issues avalue obtained by adding 1 to a latest “history ID” that is alreadyregistered in the history information 1701 as a new “history ID”,associates a “similar case ID” that is an addition object with the“history ID”, and registers the “similar case ID” in the historyinformation 1701.

Therefore, when displaying thumbnail images in the history managementregion 760, the display control unit 104 sequentially arranges thethumbnail images from a left end to a right end of the historymanagement region 760 in an ascending order of “history IDs” in thehistory information 1701. At this point, the display control unit 104may identify thumbnail image data 4500 from similar case data 4000corresponding to the “similar case ID” registered in the historyinformation 1701.

Next, the significance of accumulating similar cases in the historyinformation 1701 will be described. While thumbnail images of a largenumber of similar cases are displayed in the case display region 710,the user selects similar cases that are similar to a diagnosis objectcase from the displayed similar cases. The selected similar cases aremoved to the layout region 720. However, since there is a limit to thenumber of similar cases that can be displayed at the same time in thelayout region 720, similar cases that are overwritten and erased fromthe layout region 720 must be saved.

This is because situations may arise where the user desires to compare asimilar case erased from the layout region 720 with the diagnosis objectcase once again and, in such situations, searching a correspondingsimilar case from the case display region 710 can be a hassle for theuser.

In addition, in the present embodiment, besides a similar case draggedand dropped in the layout region 720 being registered in the historyinformation 1701, a similar case that is directly dragged and dropped inthe history management region 760 is also registered in the historyinformation 1701.

There may be cases where the user picks out, in advance, several similarcases of interest from the large number of similar cases displayed inthe case display region 710 to be viewed carefully at a later time. Insuch a case, it is useful to have a function for causing a thumbnailimage of a similar case to be directly dragged and dropped in thehistory management region 760 and have the thumbnail image displayed inthe history management region 760. Accordingly, the present embodimentis mounted with such a function.

Moreover, in the description given above, the history management region760 displays a thumbnail image dragged and dropped to the layout region720. However, this is simply an example. For example, a mode may beadopted in which the history management region 760 displays a thumbnailimage which had been originally dragged and dropped to the layout region720 but had subsequently been overwritten by another thumbnail image anderased from the layout region 720 as well as a thumbnail image that hadbeen directly dragged and dropped to the history management region 760.In this case, a thumbnail image currently being displayed in the layoutregion 720 is no longer displayed in the history management region 760.

When adopting this mode, the history information managing unit 107 mayregister similar case IDs of the thumbnail image erased from the layoutregion 720 and the thumbnail image directly dragged and dropped to thehistory management region 760 in the history information 1701.

FIG. 22 is a diagram showing a data configuration of the patientinformation 1000. The patient information 1000 is accumulated andmanaged in the patient information accumulating unit 201 for eachpatient by the patient information managing unit 202 of the medicalinformation management system 200. Personal information of a patientsuch as gender and age, clinical information of the patient such asmedical history, and examination information of the patient such as ablood test are registered in the patient information 1000. As shown inFIG. 22, the patient information 1000 includes a patient ID 1100, a name1200, an age 1300, a gender 1400, a medical history 1500, a familymedical history 1600, a chief complaint 1700, examination information1800, and a definitive diagnosis 1900.

The patient ID 1100 is an identifier unique to a patient. The name 1200,the age 1300, the gender 1400, the medical history 1500, the familymedical history 1600, and the chief complaint 1700 are, respectively,the name, the age, the gender, the medical history, the family medicalhistory, and the chief complaint of the patient represented by thepatient ID 1100. As shown in FIG. 23, the examination information 1800represents information related to one or more examinations previouslyundergone by the patient.

FIG. 23 is a diagram showing a data configuration of examinationinformation 1800 that is registered in the patient information 1000shown in FIG. 22. The examination information 1800 is informationrelated to an examination performed on a patient and is created onepiece at a time in correspondence to each examination. The examinationinformation 1800 includes an examination ID 1810, an examinationdate/time 1820, an examination type 1830, and an examination result1840. The examination ID 1810 is an identifier unique to an examination.The examination date/time 1820 represents a date and time when theexamination had been performed. The examination type 1830 represents atype of the examination. Examples of examination types include a bloodtest, a respiratory function test, an endoscopic examination, plainradiography, and a CT scan.

In a case of a blood test, various indicators including a white bloodcell count, LDH, and GPT correspond to the examination result 1840. Inaddition, for example, a judgment made by a radiologist based on variousindicators also corresponds to the examination result 1840. Furthermore,in a case of an image-based examination such as plain radiography and aCT scan, the examination result 1840 includes pointer information to aphotographed image or pointer information to a report containing animage diagnosis result. Moreover, images photographed in the course ofan examination are accumulated in the DICOM format in the medical imagedata accumulating unit 203 of the medical information management system200.

In addition, when the examination type 1830 is an image-basedexamination such as plain radiography, a CT, an MRI, and a PET, medicalimage data thereof are accumulated in a medical image database 2000stored by the medical image data accumulating unit 203 of the medicalinformation management system 200.

FIG. 24 is a diagram showing a data configuration of the medical imagedatabase 2000. The medical image database 2000 includes the examinationID 1810 and a series ID 2100. Since there are cases where a plurality oftypes of photography (for example, a plain CT and a contrast-enhancedCT) are performed in one examination, there may be cases where aplurality of series IDs 2100 are associated with one examination ID1810. In other words, the number of acquired series corresponds to thenumber of types of photography.

In addition, besides each type of photography, a series is obtained foreach reconstruction condition of a photographed image. For example, whena photographed image is reconstructed in a lung window setting and amediastinal window setting, one series is obtained for each of thesettings. Moreover, in an image reconstructed in a lung window setting,blood vessels, bronchi, alveoli, and the like of the lungs are displayedhighlighted. In addition, in an image reconstructed in a mediastinalwindow setting, a mediastinum including blood vessels and lymph nodesare displayed highlighted. Since a lung window setting and a mediastinalwindow setting are obtained by reconstructing an image obtained in onephotographic session, when two photographic sessions are performed withplain CT and contrast-enhanced CT and images are reconstructed in a lungwindow setting and a mediastinal window setting for each of the twophotographic sessions, two series in the lung window setting areobtained and two series in the mediastinal window setting are obtained.

In an image-based examination by a CT and an MRI, since a plurality ofslice images are acquired by one photographic session, a plurality ofslice IDs 2200 are associated with one series ID 2100. Since two seriesIDs “CT149123” and “CT149124” are associated with the examination ID“13227989” in FIG. 24, it is shown that two CT image series have beenobtained from the examination. It is also shown that a plurality ofslice IDs 2200 are associated with each of the series IDs “CT149123” and“CT149124”.

When the examination type 1830 is an image-based examination such asplain radiography, a CT, an MRI, and a PET, a diagnostic report 3000such as that shown in FIG. 25 is accumulated in the diagnostic reportmanaging unit 205 of the medical information management system 200. Adiagnostic result by a radiologist with respect to each examination isregistered in the diagnostic report 3000. FIG. 25 is a diagram showing adata configuration of the diagnostic report 3000.

The diagnostic report 3000 includes the examination ID 1810, findings3100, and a diagnosis 3200. The examination ID 1810 is the same as theexamination ID 1810 shown in FIG. 23. Accordingly, the diagnostic report3000 and the examination information 1800 are associated with eachother. A text representing findings of the radiologist with respect tothe examination is registered in the findings 3100. A text representinga diagnosis of the radiologist with respect to the examination isregistered in the diagnosis 3200.

FIG. 26 is a diagram showing a data configuration of similar case data4000. The similar case data 4000 is data that is referred to whenretrieving a similar case that is similar to a diagnosis object case.One piece of similar case data 4000 is created corresponding to onesimilar case. Moreover, the similar case data 4000 is an example of theadditional information of similar case data. The similar case data 4000is accumulated for each similar case in the similar case dataaccumulating unit 301 of the case retrieval system 300. As shown in FIG.26, the similar case data 4000 includes a similar case ID 4100, a sliceID 4200, region of interest information 4300, image feature data 4400,thumbnail image data 4500, lesion distribution information 4600, adefinitive diagnosis (broadly categorized disease name) 4700, and adefinitive diagnosis (finely categorized disease name) 4800.

The similar case ID 4100 is an identifier of the similar case data 4000.In this case, since one piece of similar case data is generated for eachregion of interest set in a slice image of a similar case, the similarcase ID 4100 can also be considered an identifier of a region ofinterest. In the example shown in FIG. 26, the similar case ID 4100 isconstituted by a symbol string constituted by “SIM” followed by anumeral.

The slice ID 4200 is an identifier of a slice image in which a region ofinterest is set and is the same as the slice ID 2200 shown in FIG. 24.The region of interest information 4300 is information indicating aposition of a region of interest set in the slice image. FIG. 27 is adiagram schematically showing a region of interest set in a slice image.In the example shown in FIG. 27, the region of interest is set in arectangular shape. Therefore, the region of interest information 4300 isconstituted by four values including coordinates (xl, yt) of a top leftvertex and coordinates (xr, yb) of a bottom right vertex of the regionof interest. Obviously, a region of interest may have a shape other thana rectangle. In such a case, a parameter capable of uniquely specifyingthe region is adopted as the region of interest information 4300. Forexample, when the region of interest has a circular shape, centercoordinates and a radius of a circle are adopted as the region ofinterest information 4300.

The image feature data 4400 is a feature value of a prescribed number ofdimensions (in this case, N-number of dimensions) that is extracted fromthe region of interest as defined by the region of interest information4300. The thumbnail image data 4500 is image data of a thumbnail imagegenerated to be displayed in the case display region 710 based on aslice image in the DICOM format as identified by a slice ID. In thiscase, in the thumbnail image data 4500, pixel values of a thumbnailimage are arranged in a raster scanning sequence from a top left vertexto a bottom right vertex of the thumbnail image, for example. Asdescribed earlier, a DICOM image obtained by a CT examination is a 11bit (pixel value: −1000 to +1000) image with 512×512 pixels. Inconsideration thereof, in the present embodiment, in order to facilitatedisplay of a thumbnail image, a thumbnail image with a 8 bit pixel valueis created in advance by subjecting a DICOM image that is a source ofthe thumbnail image to a low resolution process and a gradationconversion process and is registered in the similar case data 4000.Alternatively, for example, a thumbnail image may be created by themedical information management system 200 and transmitted to the caseretrieval system 300 or the case retrieval system 300 may acquire aDICOM image from the medical information management system 200 to createa thumbnail image.

The lesion distribution information 4600 is a distribution flag value(1: applicable, 0: not applicable) indicating whether or not a similarcase that is an object corresponds to any of lesion distributionsrepresented by diffuse 4610 to hematogenous 4670 determined in advance.

The definitive diagnosis (broadly categorized disease name) 4700represents a broadly categorized disease name that is confirmed withrespect to a similar case that is an object. The definitive diagnosis(broadly categorized disease name) 4700 is used when narrowing downsimilar cases by a broadly categorized disease name.

The definitive diagnosis (finely categorized disease name) 4800represents a finely categorized disease name that is confirmed withrespect to a similar case that is an object. The definitive diagnosis(finely categorized disease name) 4800 is used when narrowing downsimilar cases by a finely categorized disease name.

As for the definitive diagnosis (broadly categorized disease name) 4700,a broadly categorized disease name which uniquely corresponds to thedefinitive diagnosis (finely categorized disease name) 4800 is definedin advance and stored in the similar case data 4000 using thecorrespondence relationship.

As for the definitive diagnosis (finely categorized disease name) 4800,the series ID 2100 is identified from the slice IDs 2200 shown in FIG.24 in the medical image data accumulating unit 203. Subsequently, theexamination ID 1810 is identified by the patient informationaccumulating unit 201 from the identified series ID, correspondingpatient information 1000 (FIG. 22) is identified from the examination ID1810, and a definitive diagnosis 1900 of a corresponding patient isidentified from the identified patient information 1000.

Next, a flow from the start of a diagnostic interpretation operation tothe start of a similar case retrieval by the information terminal 100 incooperation with the medical information management system 200 and thecase retrieval system 300 will be described.

FIG. 28 is a sequence diagram showing a process in which the informationterminal 100 first acquires a diagnosis object case from the medicalinformation management system 200 and then issues a request for similarcase retrieval to the case retrieval system 300, and the case retrievalsystem 300 subsequently receives the request for similar case retrieval.Moreover, in FIG. 28, two columns of rectangles shown to the left of thesequence diagram represent screens displayed on the displays 101 a and101 b due to the processes of corresponding steps. In addition, in FIG.28, “A” shown near the information terminal represents a medicalinformation management application and “B” represents a similar caseretrieval application. It is assumed that the medical informationmanagement application has been started prior to the start of thepresent sequence.

First, the information terminal 100 accepts a display request for anexamination list to be a diagnostic interpretation object of a user (aradiologist to perform the diagnostic interpretation) through theoperating unit 102, and transmits the display request for theexamination list to the communication control unit 206 of the medicalinformation management system 200 through the input control unit 103 andthe communication control unit 110 (S510).

The patient information managing unit 202 of the medical informationmanagement system 200 lists examinations for which image-basedexamination has been performed but diagnostic interpretation has notbeen completed and generates a diagnostic interpretation objectexamination list. In addition, the patient information managing unit 202transmits the generated examination list to the communication controlunit 110 of the information terminal 100 through the communicationcontrol unit 206 (S520). In this case, the examination list includespatient information 1000 and examination information 1800 of acorresponding patient.

The display control unit 104 of the information terminal 100 displaysthe examination list received by the communication control unit 110 onthe display 101 (S530).

In this case, the display 101 a displays the examination list and thedisplay 101 b displays nothing.

FIG. 29 is a screen diagram of an examination list. The examination listincludes a region 800 for displaying examinations for which diagnosticinterpretation has not been completed and a region 810 for displayinginformation related to a series included in the examinations. Fields ofa “patient ID”, a “patient name”, an “examination date/time”, an“examination ID”, and an “examination type” are provided in the region800. The patient ID 1100 and the name 1200 registered in the patientinformation 1000 are displayed in the “patient ID” and “patient name”fields, and the examination date/time 1820, the examination ID 1810, andthe examination type 1830, which are registered in the examinationinformation 1800, are displayed in the “examination date/time”,“examination ID”, and “examination type” fields. The region 810 is aregion for displaying details of an examination selected by the user inthe region 800 and is provided with fields of a “series ID”, a“definition”, and an “image”. In this case, since an examination(corresponding to rows) have not been selected by the user in the region800, nothing is displayed in the region 810.

The user selects an examination for which diagnostic interpretation isto be performed from the examinations displayed in the region 800. Whenthe selection is sensed by the input control unit 103, as shown in FIG.28, the communication control unit 110 transmits a display request forall series included in the examination ID of the selected examination tothe medical information management system 200 (S540).

When the communication control unit 206 of the medical informationmanagement system 200 receives the display request, the patientinformation managing unit 202 refers to the medical image database 2000shown in FIG. 24, acquires all slice images of all series included inthe examination ID specified by the display request, and transmits theslice images to the information terminal 100 through the communicationcontrol unit 206 (S550). For example, in the example shown in FIG. 24,when the examination with the examination ID “13227989” is selected bythe user, all slice images included in the series with the series IDs“CT149123” and “CT149124” are transmitted in S550.

When the communication control unit 110 of the information terminal 100acquires images of all series, the display control unit 104 displays aseries list that displays information related to all series included inthe specified examination ID as a list in the region 810 (S560).

In this case, a series list of the series corresponding to theexamination selected in the region 800 is displayed in the region 810 ofthe examination list displayed on the display 101 a. Meanwhile, nothingis displayed on the display 101 b.

FIG. 30 is a screen diagram of the examination list after an examinationis selected. In the region 800 shown in FIG. 30, the background of aselected row is highlighted. In the example shown in FIG. 30, anexamination on “Taro Pana” in the second row is selected in the region800. Therefore, in the region 810, the “series ID”, the “definition”,and the “image” of the selected examination are displayed. In this case,the series ID associated with the examination ID of the selectedexamination in the medical image database 2000 is displayed in the“series ID” field and a thumbnail image of one slice image representingthe displayed series ID is displayed in the “image” field. As the oneslice image that represents the series ID, an image at a prescribedslice position is adopted. The prescribed slice position may be a topslice position or a central slice position. The “definition” indicates aphotographic condition or a reconstruction condition with respect to acorresponding series. Although not shown, for example, the “definition”is registered in association with a series ID in the medical imagedatabase 2000 shown in FIG. 24.

When a diagnostic interpretation object series is selected by the userin the region 810 and the input control unit 103 senses the selection,the display control unit 104 displays a top slice image of the selectedseries on the display 101 a as shown in FIG. 73C (S570). FIG. 73C is adiagram showing a slice image that is displayed on the display 101 awhen a series is selected by the user. FIG. 73C is a diagram showing atop slice of a chest CT radiograph and is a slice image taken at ashoulder position that is slightly closer to the head than the pulmonaryapex. At this point, the display control unit 104 displays all sliceimages of the selected series on the display 101 a so that the sliceimages can be series-fed. Meanwhile, nothing is displayed on the display101 b. For example, the user positions a mouse pointer on the display101 a and inputs a slice feeding operation by rotating a mouse wheel,whereby the input control unit 103 senses the operation. As a result,the display control unit 104 switches the slice image displayed on thedisplay 101 a to a slice image at a different slice position inaccordance with an amount of rotation of the mouse wheel. The userperforms image diagnosis while inputting a slice feeding operation. Inaddition, when the user hesitates in performing the image diagnosis, theuser starts the similar case retrieval application.

At this point, the similar case retrieval application may be startedwhen a shortcut key determined in advance is input on a keyboard of theoperating unit 102 or when a menu of a medical image viewer is displayedby a right click of the mouse and a similar case retrieval menu isspecified from the menu. When an instruction to start the similar caseretrieval application is issued, management of the information terminal100 is handed over to the ROI managing unit 105 and the informationterminal 100 enters a region of interest (ROI) standby state.

The user sets a region of interest (ROI) to a lesion on the slice imagedisplayed on the display 101 a through the operating unit 102 (S580). Atthis point, as shown in FIG. 27, for example, the user left-clicks themouse to input coordinates of a top left vertex of the region ofinterest. Subsequently, the user may input a bottom right vertex of theregion of interest by dragging the mouse diagonally rightward anddownward while holding the left click of the mouse and then releasingthe left click. FIG. 31 shows an example of a screen after a region ofinterest has been set with respect to a lesion.

When the input control unit 103 senses an operation for setting a regionof interest, the ROI managing unit 105 receives coordinate data of thetop left and bottom right vertices of the region of interest from theinput control unit 103 and generates region of interest information withthe received coordinate data. In addition, the ROI managing unit 105transmits the generated region of interest information to thecommunication control unit 110 (S590).

At the same time, the ROI managing unit 105 transmits a slice image ofthe diagnosis object case to the communication control unit 110 (S600).In this case, in S550, one slice image (retrieval query image) to whicha region of interest has been set by the user in a series selected bythe user is transmitted among the slice images of all series received bythe information terminal 100 from the medical information managementsystem 200.

Next, the communication control unit 110 receives the region of interestinformation transmitted from the ROI managing unit 105 and transmits theregion of interest information to the communication control unit 304 ofthe case retrieval system 300 (S601).

At the same time, the communication control unit 110 receives the sliceimage transmitted from the ROI managing unit 105 and transmits the sliceimage to the communication control unit 304 of the case retrieval system300 (S602).

While a slice image itself is transmitted in S600 and S601, only a sliceID of the slice image may be transmitted instead. In this case, the caseretrieval system 300 having received the slice ID may acquire a sliceimage from the medical information management system 200 by specifyingthe slice ID.

Next, a process until the case retrieval system 300 performs similarcase retrieval and the information terminal 100 initially displays asimilar case retrieval result will be described.

FIG. 32 is a sequence diagram showing a process in which, after the caseretrieval system 300 receives a request for similar case retrieval, thecase retrieval system 300 sends back a similar case retrieval result tothe information terminal 100.

The image feature extracting unit 302 of the case retrieval system 300extracts an image feature of a plurality of number of dimensionsdetermined in advance from the region of interest set in the retrievalquery image (S610).

As an “image feature”, an image feature related to a shape of an organor a lesion portion in a medical image, an image feature related tobrightness distribution, or the like can be adopted. For example, NonPatent Literature “Nemoto, Shimizu, Hagihara, Kobatake, and Nawano;Improvement of Tumor Detection Performance in Mammograms by FeatureSelection from a Large Number of Features and Proposal of Fast FeatureSelection Method; IEICE TRANSACTIONS on Information and Systems D-II,Vol. J88-D-II, No. 2, pp. 416-426, February 2005” describes using animage feature with 490 dimensions. In the present embodiment, forexample, the image feature described in this Non Patent Literature isadopted. However, this is simply an example and other image features maybe adopted instead.

The similar case retrieving unit 303 compares the image featureextracted by the image feature extracting unit 302 and an image featureof each similar case accumulated in the similar case data accumulatingunit 301 with each other (S620). At this point, the similar caseretrieving unit 303 compares both image features with each other bycalculating a distance between image feature data extracted from theretrieval query image and image feature data 4400 registered in thesimilar case data 4000 (FIG. 26) accumulated for each similar case inthe similar case data accumulating unit 301.

Next, the similar case retrieving unit 303 sorts similar cases withdistances that are equal to or shorter than a prescribed threshold in anascending order of distance and decides the similar cases to betransmission objects (S630). Next, among the similar case data 4000accumulated in the similar case data accumulating unit 301, thecommunication control unit 304 transmits the similar case ID 4100, theslice ID 4200, the region of interest information 4300, the thumbnailimage data 4500, the lesion distribution information 4600, thedefinitive diagnosis (broadly categorized disease name) 4700, and thedefinitive diagnosis (finely categorized disease name) 4800 of a similarcase decided as the transmission object as well as the distancecalculated by the similar case retrieving unit 303 to the informationterminal 100 (S640).

Hereinafter, a process is executed for generating an initial basicscreen K2 (FIG. 6) on which a similar case retrieval result isdisplayed. First, management information that is used when generatingthe layout region 720 on the initial basic screen K2 will be described.

First, the communication control unit 304 of the case retrieval system300 transmits layout information to the information terminal 100 (S650).In this case, layout information refers to information that specifiesthe number of rows and the number of columns of display boxesconstituting the layout region 720.

Next, when the communication control unit 110 of the informationterminal 100 receives the layout information, the display box managingunit 106 registers the number of rows and the number of columns ofdisplay boxes specified by the transmitted layout information in displaybox management information 4410 (FIG. 44) and, at the same time,registers the slice ID of the retrieval query image in display boxmanagement information (FIG. 44) (S660).

FIG. 44 is a diagram showing a data configuration of the display boxmanagement information 4410. The display box management information 4410includes a table 4411 in which number of rows and the number of columnsare registered and a table 4412 in which a slice ID of the slice imagedisplayed in each display box is registered. Therefore, the display boxmanaging unit 106 registers the number of rows and the number of columnsof display boxes specified by the layout information transmitted fromthe case retrieval system 300 in the number of row field and the numberof column field of the table 4411. In addition, in the presentembodiment, a thumbnail image of the retrieval query image is displayedin a top left display box 721 among the four display boxes 721 to 724.Therefore, the display box managing unit 106 registers the slice ID ofthe retrieval query image transmitted from the medical informationmanagement system 200 in a 1st-row, 1st-column item of the table 4412.

In this case, default values of the number of rows and the number ofcolumns of display boxes constituting the layout region 720 are set inadvance by the case retrieval system 300. The default values of thenumber of rows and the number of columns are, for example, two rows andtwo columns. Therefore, “2 rows and 2 columns” are registered in thedisplay box management information 4410 shown in FIG. 44.

In the example shown in FIG. 6, the display boxes 721 to 724 aredisplayed in two rows and two columns in the layout region 720. Thenumber of rows and the number of columns in the layout region 720 can beset at will by the user.

FIG. 41 is a diagram showing the basic screen K2 having the layoutregion 720 in which display boxes are set in three rows and two columns.If the display boxes constituting the layout region 720 are to begeneralized as M rows and N columns, when M≠N, it is desirable that M>Nwhen the display 101 is an upright display and desirable that M<N whenthe display 101 is a horizontal display.

An important feature of the present embodiment is that a thumbnail imageof a diagnosis object case is displayed in one display box among thedisplay boxes constituting the layout region 720. In other words, bydisplaying a similar case and a diagnosis object case adjacent to eachother, the user can more easily determine the degree of similaritybetween both cases. Therefore, the arrangement of the display boxes inthe layout region 720 is desirably set to three rows and three columnsat the most.

In addition, when the arrangement of the display boxes is three rows andtwo columns, the thumbnail image of the retrieval query image isfavorably displayed in the 2nd-row, 1 st-column display box or the2nd-row, 2nd-column display box. Furthermore, when the arrangement ofthe display boxes is two rows and three columns, the thumbnail image ofthe retrieval query image is favorably displayed in the 1st-row,2nd-column display box or the 2nd-row, 2nd-column display box. Moreover,when the arrangement of the display boxes is three rows and threecolumns, the thumbnail image of the retrieval query image is favorablydisplayed in the 2nd-row, 2nd-column display box. Accordingly, thesimilar case is to be always displayed adjacent to the diagnosis objectcase in the layout region 720.

Layout information of the layout region 720 set by the user isregistered in layout management information 4200 shown in FIG. 42 or 43.

Moreover, the box layout managing unit 111 that stores the layoutmanagement information 4200 may be included in the case retrieval system300.

Even for the same user, a layout of the layout region 720 may be changedso as to accommodate a size or a screen type (upright or horizontal) ofthe display 101 of the information terminal 100. Therefore, as shown inFIG. 43, the layout information set by the user may be registered in thelayout management information 4200 in association with a user ID and aterminal ID. FIG. 43 is a diagram showing an example of the layoutmanagement information 4200. In the layout management information 4200,a “user ID”, a “terminal ID”, the “number of columns”, the “number ofrows”, and a “position of diagnosis object case” are associated witheach other. In this case, the “user ID” is an identifier that isassigned to a user who uses the information terminal 100 in advance. The“terminal ID” is an identifier of the information terminal 100 that isexpected to be used by a corresponding user.

In the example shown in FIG. 43, since the user with a user ID “U01” isexpected to use terminal IDs “T02” and “T04”, the user ID “U01” isassociated with the terminal IDs “T02” and “T04”. The number of rows andthe number of columns of the layout region 720 as set by a correspondinguser are registered in the “number of columns” and the “number of rows”.The “position of diagnosis object case” represents a position of adisplay box that displays the diagnosis object case. For example, in theinformation terminal 100 with the terminal ID “T04”, the layout region720 is set to two rows and three columns, and (2,1) indicating the 2ndrow and 1st column is registered as the “position of diagnosis objectcase” so that the diagnosis object case is displayed adjacent to all ofthe similar cases.

Moreover, while a mode in which layout information is managed inassociation with a user ID and a terminal ID has been shown in FIG. 43,layout information may be managed in association with only a user ID.FIG. 42 is a diagram showing an example of the layout managementinformation 4200. In the layout management information 4200 shown inFIG. 42, the “terminal ID” field has been omitted from the layoutmanagement information 4200 shown in FIG. 43. Otherwise, the layoutmanagement information 4200 shown in FIG. 42 is the same as the layoutmanagement information 4200 shown in FIG. 43. Moreover, in the modeshown in FIG. 42, since one user had been expected to use oneinformation terminal 100, the “terminal ID” field is omitted.

When layout information is managed by the case retrieval system 300,layout information of a corresponding user is transmitted to theinformation terminal 100 in S650 in FIG. 32.

Next, using the similar case data transmitted in S640 and the displaybox management information 4410 stored in S660, the display control unit104 generates the initial basic screen K2 on which a similar caseretrieval result is displayed (S670).

In this case, the basic screen K2 shown in FIG. 6 is displayed on thedisplay 101 b. In addition, the retrieval query image is displayed onthe display 101 a.

FIG. 33 is a flow chart showing details of the process for generatingthe initial basic screen K2 shown in S670 in FIG. 32.

First, in S1000, the display control unit 104 counts the number ofsimilar cases received in S640 shown in FIG. 32 and displays the countvalue in the number of retrieved results display region 713.

Next, in S1100, the display control unit 104 displays “all disorders” inthe display condition display region 714. “All disorders” is displayedat this point because, on the initial basic screen K2, similar caseshave not yet been narrowed down by a disease name or a lesiondistribution by the user.

Next, in S1200, the display control unit 104 displays thumbnail imagesof similar cases in the case display region 710 for the number ofsimilar cases for which thumbnail images can be displayed in the casedisplay region 710 among the similar cases received in S640 shown inFIG. 32 and, at the same time, displays a definitive diagnosis and adegree of similarity in association with each thumbnail image.

In the example shown in FIG. 6, the maximum value of the number ofsimilar cases that can be displayed in the case display region 710 is20. This maximum value is determined in advance. Alternatively, aconfiguration may be adopted in which the user can change the maximumvalue at will. When the number of similar cases received in S640 shownin FIG. 32 is larger than the maximum value, the display control unit104 displays the scroll bar 715 that is elongated in a verticaldirection at a right end of the case display region 710. Accordingly,the user can move the scroll bar 715 and view thumbnail images ofsimilar cases which had been hidden on the initial basic screen K2.

Next, in S1300, a disease name list is generated and displayed. First, adisease name list is generated from the similar cases received in S640shown in FIG. 32. The disease name list is a list in which the similarcases received in S640 are classified according to definitivelydiagnosed disease names.

Let us assume that the number of similar cases received in S640 isexpressed as NC. The disease name list managing unit 108 generates thedisease name list using the definitive diagnosis (broadly categorizeddisease name) 4700 and the definitive diagnosis (finely categorizeddisease name) 4800 respectively registered in the NC-number of pieces ofsimilar case data 4000. The generated disease name list is managed bythe disease name list managing unit 108 as table format data as shown inFIG. 35.

FIG. 35 is a diagram showing a data configuration of a disease name listthat is generated in S1300 shown in FIG. 33. The disease name listincludes fields of a “disease name ID”, a “broadly categorized diseasename”, a “finely categorized disease name”, the “number of cases”, and a“similar case ID”. The “disease name ID” is an identifier assigned toeach definitively diagnosed disease name. In this case, one disease nameID is assigned to one combination of a broadly categorized disease nameand a finely categorized disease name.

The “broadly categorized disease name” is the definitively diagnoseddisease name represented by the definitive diagnosis (broadlycategorized disease name) 4700 registered in the similar case data 4000.The “finely categorized disease name” is the definitively diagnoseddisease name represented by the definitive diagnosis (finely categorizeddisease name) 4800 registered in the similar case data 4000. The “numberof cases” is the number of similar eases corresponding to thedefinitively diagnosed disease name represented by the “disease nameID”. The “similar case ID” is a similar case ID representing a similarcase corresponding to the disease name represented by the “disease nameID”.

The disease name list managing unit 108 extracts the definitivediagnosis (broadly categorized disease name) 4700 and the definitivediagnosis (finely categorized disease name) 4800 for all pieces ofsimilar case data 4000 received in S640 and classifies the same similarcase data 4000 as the similar case of a same definitively diagnoseddisease name for both definitive diagnoses. In addition, the diseasename list managing unit 108 counts the number of similar cases with thesame definitively diagnosed disease name and registers the number ofsimilar cases in the “number of cases” field in a record of acorresponding definitively diagnosed disease name. Furthermore, thedisease name list managing unit 108 registers a similar case ID of asimilar case classified as a same definitively diagnosed disease name inthe “similar case ID” field in a record of a corresponding definitivelydiagnosed disease name.

In the example shown in FIG. 35, a disease name ID “DIS528” is assignedto a definitively diagnosed disease name whose broadly categorizeddisease name is “neoplastic” and whose finely categorized disease nameis “lung cancer”. In addition, since the number of similar casescorresponding to the definitively diagnosed disease name is 10, 10 isregistered in the “number of cases” field of a corresponding record andsimilar case IDs “SIM258”, “SIM551”, “SIM1209”, “SIM2341”, and the likeof similar cases corresponding to the definitively diagnosed diseasename are registered in the “similar case ID” field of the correspondingrecord.

Subsequently, the display control unit 104 generates the disease namelist display region 730 using the disease name list generated asdescribed above and displays the disease name list display region 730 onthe display 101.

FIGS. 36, 37, and 38 are, respectively, diagrams showing a first displayexample, a second display example, and a third display example of thedisease name list display region 730. As shown in FIG. 36, in the firstdisplay example, similar cases obtained as a result of a similar caseretrieval are displayed associated with the number of cases of a finelycategorized disease name in a descending order of the number of cases asa list.

As shown in FIG. 37, in the second display example, similar casesobtained as a result of a similar case retrieval are displayedassociated with the number of cases of a broadly categorized diseasename in a descending order of the number of cases as a list.

As shown in FIG. 38, in the third display example, similar casesobtained as a result of a similar case retrieval are displayedassociated with the number of cases of a broadly categorized diseasename in a descending order of the number of cases as a list and, foreach broadly categorized disease name, the finely categorized diseasenames included in the broadly categorized disease name are displayedassociated with the number of cases in a descending order of the numberof cases as a list. In this case, a definitively diagnosed disease nameis expressed by a hierarchical structure of a broadly categorizeddisease name and a finely categorized disease name.

FIG. 39 is a diagram showing a screen transition of the disease namelist display region 730 shown in FIG. 37. As shown in an upper part ofFIG. 39, when the input control unit 103 senses an operation by a userfor selecting one broadly categorized disease name among the broadlycategorized disease names displayed as a list, the display control unit104 displays the finely categorized disease names belonging to theselected broadly categorized disease name in association with the numberof cases in a descending order of the number of cases as shown in alower part of FIG. 39. At this point, for example, the user may selectone broadly categorized disease name by double-clicking orsingle-clicking one desired broadly categorized disease name among thebroadly categorized disease names displayed as a list in the diseasename list display region 730. In the example shown in FIG. 39, sincenonneoplastic has been double-clicked, the finely categorized diseasenames belonging to nonneoplastic are displayed as a list.

In the lower part of FIG. 39, when a region in which the finelycategorized disease names are displayed as a list is double-clicked orsingle-clicked by the user, the display control unit 104 may hide thefinely categorized disease names that had been displayed in thecorresponding region.

Moreover, the display control unit 104 may judge the finely categorizeddisease names belonging to the broadly categorized disease name byreferring to the disease name list (FIG. 35). For example, in theexample shown in FIG. 35, since aspergillosis and cryptococcosis areassociated with mycosis, the display control unit 104 may determine thataspergillosis and cryptococcosis belong to mycosis.

Returning now to FIG. 33, in S1400, a distribution list is generated anddisplayed. First, a distribution list is generated from the similarcases received in S640. The distribution list is a list in which thesimilar cases received in S640 are classified according to lesiondistributions.

The disease name list managing unit 108 generates a distribution listusing lesion distribution information 4600 registered in each similarcase data 4000 of the NC-number of cases. The generated distributionlist is managed by the distribution list managing unit 109 as tableformat data as shown in FIG. 40.

FIG. 40 is a diagram showing a data configuration of a distribution listthat is generated in S1400 shown in FIG. 33. The disease name listincludes fields of a “distribution name”, the “number of cases”, and a“similar case ID”. The “distribution name” is a name of plurality oflesion distributions determined in advance such as diffuse andsegmental. The “number of cases” represents the number of similar casescorresponding to a lesion distribution. The “similar case ID” is asimilar case ID representing a similar case corresponding to a lesiondistribution.

The distribution list managing unit 109 extracts lesion distributioninformation 4600 for all pieces of similar case data 4000 received inS640, counts the number of lesion distributions for which 1 (applicable)is set to the distribution flag value in the extracted lesiondistribution information 4600, and registers the count value in the“number of cases” field of a record of a corresponding lesiondistribution. In addition, the distribution list managing unit 109registers a similar case ID of a similar case for which 1 is set to thedistribution flag value in the “similar case ID” field in the record ofa corresponding lesion distribution.

In the example shown in FIG. 40, since there are three similar casescorresponding to diffuse, 3 is registered in the “number of cases” ofthe record of diffuse. In addition, similar case IDs “SIM2521”,“SIM4123”, and “SIM5225” representing similar cases corresponding todiffuse are registered in the “similar case ID” field of the record ofdiffuse.

Subsequently, the display control unit 104 generates the distributionlist display region 750 using the distribution list generated asdescribed above and displays the distribution list display region 750 onthe display 101.

FIG. 11 shows the distribution list display region 750 generated usingthe distribution list shown in FIG. 40. In FIG. 40, since the numbers ofcases of segmental and subpleural are zero, in FIG. 11, segmental 752and subpleural 756 are displayed in an inactive state and since otherlesion distributions have one or more cases, the other lesiondistributions are displayed in an active state.

Returning now to FIG. 33, in S1500, the layout region 720 is displayed.This process is performed by the display control unit 104.

FIG. 34 is a flow chart showing a process of S1500 shown in FIG. 33. InS1510, the display control unit 104 acquires the number of rows and thenumber of columns of display boxes constituting the layout region 720from the display box management information 4410 set in S660. In theexample of the display box management information 4410 shown in FIG. 44,since two rows and two columns are set as the number of rows and thenumber of columns, information reading “2 rows and 2 columns” isacquired. Moreover, when the user has changed the number of rows and thenumber of columns of display boxes, the number of rows and the number ofcolumns of display boxes constituting the layout region 720 are acquiredfrom the layout management information 4200 shown in FIG. 42 or 43.

Next, in S1520, the display control unit 104 draws display boxes inaccordance with the number of rows and the number of columns of displayboxes acquired in S1510.

Finally, in S1530, the display control unit 104 identifies a slice ID ofeach display box from the display box management information 4410 anddraws a thumbnail image corresponding to the identified slice ID in eachcorresponding display box.

In the example shown in FIG. 44, the slice ID of a diagnosis object caseis stored in the 1st-row, 1st-column display box. Therefore, the displaycontrol unit 104 generates a thumbnail image from the slice ID of thediagnosis object case transmitted in S600 shown in FIG. 28 and draws thegenerated thumbnail image in the display box 721.

At this stage, since slice IDs are not stored in the remaining displayboxes (the 1st-row, 2nd-column display box 722, the 2nd-row, 1 st-columndisplay box 723, and the 2nd-row, 2nd-column display box 724), thedisplay control unit 104 does not display anything in these displayboxes. A thumbnail image of a similar case is to be displayed in thesedisplay boxes by a process to be described later.

Returning now to FIG. 32, the communication control unit 110 transmitsthe display box management information 4410 stored in the display boxmanaging unit 106 to the display control unit 104 (S680).

Next, the display control unit 104 starts a medical image viewer in asame display state and a same layout as a display state and a layout ofthe layout region 720 (S690).

FIG. 45 is a flow chart showing a starting process of a medical imageviewer.

In S2000, the display control unit 104 closes the medical image viewerstarted in S570 in FIG. 28.

In S2100, the display control unit 104 starts medical image viewerscorresponding to the number of display boxes registered in the displaybox management information 4410 in a layout with the number of rows andthe number of columns registered in the display box managementinformation 4410. In the display box management information 4410 shownin FIG. 44, four display boxes are registered in two rows and twocolumns. Therefore, as shown in FIG. 5, the display control unit 104starts the four medical image viewers 610 to 640 in two rows and twocolumns. Moreover, when the number of rows and the number of columns ofthe layout region 720 is changed by the user, the medical image viewerscorresponding to the number of display boxes registered in the layoutmanagement information 4200 shown in FIG. 42 or 43 are started in alayout with the number of rows and the number of columns registered inthe layout management information 4200.

In S2200, the display control unit 104 initializes a variable foridentifying a medical image viewer that is a processing object. In thiscase, since the 1st-row, 1 st-column medical image viewer is theprocessing object, the variable is set to the 1st-row and 1st-column.

In S2300, the display control unit 104 checks whether or not processingof all (in this case, four) medical image viewers has been completed. Ifprocessed (YES in S2300), the process is completed, and if there is anunprocessed medical image viewer (NO in S2300), the process is advancedto S2400.

In S2400, the display control unit 104 displays a slice image having aslice ID associated with the number of rows and the number of columnsset as a variable on the medical image viewer that is the processingobject and associates a series including the slice ID with the medicalimage viewer.

For example, in the example of the display box management information4410 shown in FIG. 44, a slice ID “CT12353515” is registered in the1st-row, 1st-column. Therefore, the slice ID “CT12353515” is displayedon the medical image viewer 610. In addition, the display control unit104 draws a rectangle representing a region of interest set in theinitially displayed slice image so as to overlap with the slice image.The series including the slice ID registered in the 1st-row, 1st-columnhas already been acquired in S550 in FIG. 28. Furthermore, the region ofinterest has already been acquired in S580 in FIG. 28.

Returning now to FIG. 45, in S2500, a next medical image viewer is setas the medical image viewer that is a processing object. Processingobjects are set so that, for example, the 1st-row, 1 st-column isfollowed by the 1st-row, 2nd-column, which in turn is followed by the2nd-row, 1 st-column, which in turn is followed by the 2nd-row,2nd-column, and so on.

In S2400 of a second loop, while the medical image viewer 620 of the1st-row, 2nd-column becomes the processing object, a slice ID is notassociated with a medical image viewer other than that of the 1st-row, 1st-column in the display box management information 4410 shown in FIG.44. Therefore, the display control unit 104 does not execute any processon the 1st-row, 2nd-column medical image viewer and leaves the medicalimage viewer in a blank state. The same applies to the 2nd-row, 1st-column medical image viewer 630 and the 2nd-row, 2nd-column medicalimage viewer 640.

Upon conclusion of the flow chart, the initial-state basic screen K1shown in FIG. 5 is displayed on the display 101 a. On the 1st-row, 1st-column (top left) medical image viewer 610, the retrieval query imageis displayed and a region of interest is drawn on top of the retrievalquery image so as to overlap with the retrieval query image.

While an example in which the case retrieval system 300 extracts animage feature has been shown, alternatively, the information terminal100 may extract an image feature. FIG. 46 is a block diagram of theinformation terminal 100, the medical information management system 200,and the case retrieval system 300 when a mode is adopted in which thecase retrieval system 300 extracts an image feature.

Differences from FIG. 2 are that the image feature extracting unit 112has been added to the information terminal 100 and that the imagefeature extracting unit 302 has been omitted from the case retrievalsystem 300.

FIG. 47 is a sequence diagram showing a process in which, after theinformation terminal 100 acquires a diagnosis object case from themedical information management system 200, the case retrieval system 300receives a request for similar case retrieval.

Differences from FIG. 28 are that, after a process by the ROI managingunit 105 for transmitting a slice image of a diagnosis object case tothe communication control unit 110 (S600), extraction of an imagefeature is performed by the information terminal 100 (S603) and theextracted image feature is transmitted to the case retrieval system 300(S604). The process content of image feature extraction (S604) issimilar to the image feature extraction performed by the case retrievalsystem 300.

FIG. 48 is a sequence diagram showing a process in which, after the caseretrieval system 300 receives a request for similar case retrieval, thecase retrieval system 300 sends back a similar case retrieval result tothe information terminal 100. A difference from FIG. 32 is that, sinceimage feature extraction is performed by the information terminal 100,the image feature extraction (S610) included in FIG. 32 has been omittedin FIG. 48.

Next, a process that is performed when a thumbnail image of a similarcase is dragged and dropped on the information terminal 100 will bedescribed.

FIG. 49 is a sequence diagram showing a process when a thumbnail imageof a similar case is dragged and dropped on the information terminal100.

In S800, the input control unit 103 senses a movement of a thumbnailimage of a similar case to a display box. FIG. 50 is a flow chartshowing details of the process of S800 shown in FIG. 49.

The input control unit 103 of the information terminal 100 constantlymonitors input made via the operating unit 102 that is a mouse or thelike. In addition, when the input control unit 103 senses that anoperation for clicking the mouse is input by the user and the operationcauses one thumbnail image of a similar case displayed in the casedisplay region 710 to be selected (YES in S3000), the display controlunit 104 changes a color of a background of the selected thumbnail image(S3100). On the other hand, when the input control unit 103 does notsense that a thumbnail image has been selected (NO in S3000), theprocess is returned to S3000. FIG. 51 is a diagram showing the basicscreen K2 when one thumbnail image among the thumbnail images displayedin the case display region 710 is selected.

In the example shown in FIG. 51, in the case display region 710, athumbnail image of a similar case displayed in the 1st-row, 4th-columnhas been selected. Therefore, the color of the background of thethumbnail image has been changed. Specifically, a color of a frame-likeregion enclosing an outer periphery of the selected thumbnail image hasbeen changed. Accordingly, the user can be notified that the thumbnailimage has changed to a selected state.

In this case, as the color of the background, for example, a color thatclearly differs from a color of a background of the case display region710 is adopted. In the example shown in FIG. 51, for example, yellow isadopted. Moreover, while a mode in which the color of a frame-likeregion of a thumbnail image is changed has been shown in the example inFIG. 51, a mode in which the frame-like region blinks or a mode in whichbrightness of the frame-like region is increased may be adopted instead.

Next, when the input control unit 103 senses an operation for draggingthe thumbnail image (YES in S3200), the display control unit 104, asshown in FIG. 52, generates a translucent duplicate 710X including thethumbnail image and the frame-like region enclosing the thumbnail imageand moves and displays the duplicate 710X so as to track the draggingoperation (S3300). On the other hand, when the input control unit 103does not sense an operation for dragging the thumbnail image (NO inS3200), the process is returned to S3000.

FIG. 52 is a diagram showing the one thumbnail image selected in FIG. 51being dragged. In addition, in S3300, the display control unit 104changes a color of an arrow symbol 770 that connects the case displayregion 710 and the layout region 720 and a color of a frame region 780that enclose the layout region 720. Accordingly, the user is prompted tocontinuously execute an operation for dragging the thumbnail imagetoward the layout region 720.

Moreover, while a mode in which colors of the arrow symbol 770 and theframe region 780 has been shown in FIG. 52, a mode in which brightnessof the arrow symbol 770 and the frame region 780 is increased or a modein which the arrow symbol 770 and the frame region 780 blink may beadopted instead.

When the user further continues the dragging operation and the inputcontrol unit 103 senses that a position of the mouse cursor has enteredany of the display boxes 721 to 724 in the layout region 720 (YES inS3400), the display control unit 104 changes a color of any one of thedisplay boxes 722 to 724 as shown in FIG. 53 (S3500). On the other hand,when the input control unit 103 does not sense that a position of themouse cursor has entered the layout region 720 (NO in S3400), theprocess is advanced to S3600.

FIG. 53 is a diagram showing a basic screen on which a color of thedisplay box 722 has been changed. In the example shown in FIG. 53, sincethe mouse cursor has entered the top right (1st-row, 2nd-column) displaybox 722, the color of the display box 722 has been changed. In thiscase, as the changed color of the display box 722, for example, a colorthat is clearly different from the color of the background of thedisplay box 722 is adopted. In the example shown in FIG. 53, the displaybox 722 is changed to, for example, blue.

Accordingly, when dragging is ended at this stage, the user can benotified that the thumbnail image is to be displayed in the display box722. While a mode in which the color of the display box 722 is changedhas been shown, a mode in which brightness of the display box 722 isincreased or the display box 722 blinks may be adopted instead.

Subsequently, when the input control unit 103 senses an operation forending the dragging (YES in S3600), the input control unit 103 judgeswhether or not the position of the mouse cursor at the end of thedragging is inside the layout region 720 (S3700). On the other hand,when the input control unit 103 does not sense an operation for endingthe dragging (NO in S3600), the process is returned to S3300. Inaddition, when the position of the mouse cursor at the end of thedragging is not inside the layout region 720 (NO in S3700), the inputcontrol unit 103 returns the process to S3700. In this case, forexample, if a left button of the mouse had been clicked at the start ofdragging, an operation for releasing the left button corresponds to theoperation for ending the dragging.

When the input control unit 103 judges that the position of the mousecursor at the end of the dragging is inside the layout region 720 (YESin S3700), as shown in FIG. 54, the display control unit 104 displaysthe selected thumbnail image in any of the display boxes 722 to 724(S3800). At this point, the duplicate 710X is erased. FIG. 54 is adiagram showing the basic screen K2 when the thumbnail image isdisplayed in the layout region 720.

Accordingly, the thumbnail image of the diagnosis object case and thethumbnail image of the similar case selected by the user are displayedadjacent to each other, albeit in small image sizes. Therefore, the usercan readily compare the two thumbnail images with each other. In thiscase, a thumbnail image is displayed in any of the display boxes 722 to724 because the thumbnail image of the diagnosis object case is alreadydisplayed in the display box 721. Moreover, when the position of themouse cursor at the end of the dragging is inside the display box 721,the display control unit 104 may display the selected thumbnail image inany one of the display boxes in which a thumbnail image is notdisplayed. This concludes S800.

Returning now to FIG. 49, when the thumbnail image of the similar caseis displayed in the display box 722, the display box managing unit 106refers to the similar case data 4000 (FIG. 26) of the displayedthumbnail image, registers a slice ID corresponding to the thumbnailimage in the display box management information 4410 (FIG. 44), andupdates the display box management information 4410 (S810). In theexample in FIG. 54, a thumbnail image is dropped in the 1st-row,2nd-column display box 722. Therefore, the slice ID 4200 registered inthe similar case data 4000 (FIG. 26) of the selected thumbnail image isregistered in the 1st-row, 2nd-column field of the table 4412 in FIG.44.

FIG. 55 is a diagram showing the display box management information 4410in which a slice ID of a similar case has been registered. As isapparent from a comparison with FIG. 44, a slice ID “CT34298362” isnewly registered in the 1st-row, 2nd-column field of the table 4412 ofthe display box management information 4410 shown in FIG. 55 and a sliceID of a similar case displayed in the layout region 720 is registered.

Returning to FIG. 49, when the display box management information 4410is updated, the display box managing unit 106 notifies a slice IDrelated to the update to the communication control unit 110 (S820). Whenviewing this process from the perspective of application layers, theslice ID is notified by the similar case retrieval application “B” tothe medical information management application “A” (S820).

The communication control unit 110 to which the slice ID is handed overtransmits the slice ID to the communication control unit 206 of themedical information management system 200 (S821).

Upon receiving the slice ID, the communication control unit 206 notifiesthe slice ID to the medical image data managing unit 204. The medicalimage data managing unit 204 refers to the medical image database 2000(FIG. 24) and identifies a series ID including the slice ID, acquiresall slice images of the series represented by the identified slice ID(S830), and hands over the slice images to the communication controlunit 206. Subsequently, the communication control unit 206 transmits allslice images of the acquired series to the communication control unit110 of the information terminal 100 (S840). When the communicationcontrol unit 110 receives all of the slice images, the display controlunit 104 displays the slice images of the slice ID on a medical imageviewer corresponding to the display box to which the slice ID has beenregistered in S810 (S850) and, at the same time, expands all sliceimages including the slice ID on a display memory corresponding to themedical image viewer. FIG. 56 is a diagram showing the basic screen K1of the display 101 a when a slice image is displayed on a medical imageviewer. In the example shown in FIG. 56, a slice image is displayed onthe medical image viewer 620. This is because the user had displayed thethumbnail image of the similar case in the display box 722.

As described above, when thumbnail images of a large number of similarcases displayed in the case display region 710 are dragged to the layoutregion 720, a thumbnail image of a diagnosis object case initiallydisplayed after starting the similar case retrieval application and athumbnail image of a similar case are displayed adjacent to each otherin the layout region 720. Therefore, the user can compare the thumbnailimages and determine a degree of similarity between cases in a simplemanner.

In addition, a diagnosis object case and a similar case are displayed ona medical image viewer on the display 101 a in a same image arrangementas the image arrangement in the layout region 720.

The user can compare a diagnosis object case and a similar case whileslice-feeding and determine a degree of similarity in detail. FIGS. 57to 60 are diagrams showing display relationships between the twodisplays 101 a and 101 b. Moreover, in FIGS. 57 to 60, upper partsrepresent the basic screen K1 that is displayed on the display 101 a andlower parts represent the basic screen K2 that is displayed on thedisplay 101 b.

FIG. 57 shows the basic screens K1 and K2 displayed on the displays 101a and 101 b immediately following start-up of the similar case retrievalapplication. Immediately following the start-up of the similar caseretrieval application, a thumbnail image of a diagnosis object case isdisplayed in the display box 721 in the layout region 720 of the basicscreen K2. Thumbnail images are not displayed in the other display boxes722 to 724.

In conjunction therewith, on the basic screen K1, a slice image of thediagnosis object case is displayed on the medical image viewer 610corresponding to the display box 721.

In FIG. 58, in the case display region 710 on the basic screen K2, athumbnail image 5801 of the 1st-row, 4th-column similar case is selectedand the thumbnail image 5801 is dragged to the display box 724.Therefore, on the basic screen K1, a slice image corresponding to thedragged thumbnail image 5801 is displayed on the medical image viewer640 corresponding to the display box 724.

In FIG. 59, in the case display region 710 on the basic screen K2, athumbnail image 5901 of the 3rd-row, 3rd-column similar case is selectedand the thumbnail image 5901 is dragged to the display box 722.Therefore, on the basic screen K1, a slice image corresponding to thedragged thumbnail image 5901 is displayed on the medical image viewer620 corresponding to the display box 722.

In FIG. 60, in the case display region 710 on the basic screen K2, athumbnail image 6001 of the 1st-row, 5th-column similar case is selectedand the thumbnail image 6001 is dragged to the display box 723.Therefore, on the basic screen K1, a slice image corresponding to thedragged thumbnail image 6001 is displayed on the medical image viewer630 corresponding to the display box 723.

In FIG. 60, thumbnail images fill all of the display boxes in the layoutregion 720. In this state, when the user wishes to further display athumbnail image of a new similar case, the user need only drag thethumbnail image to a display box in the layout region 720 in the samemanner as when all of the display boxes are not filled with thumbnailimages (FIG. 61).

FIG. 61 is a diagram showing the basic screen K2 in a state in which alldisplay boxes are filled with thumbnail images and another thumbnailimage is being dragged. In the example shown in FIG. 61, in the casedisplay region 710, since a 2nd-row, 2nd-column thumbnail image 6101 hasbeen selected and then dragged, a duplicate 6101X of the thumbnail image6101 is displayed. In addition, the user is dragging the duplicate 6101Xtoward the layout region 720.

Let us assume that, at this point, the user has dropped the duplicate6101X at the display box 722. In this case, the duplicate 6101X becomeshidden and the thumbnail image 6101 overwrites the display box 722.Accordingly, the thumbnail image 6101 is displayed in the display box722 in place of a previously displayed thumbnail image.

In conjunction with the overwriting, the medical image viewer 620corresponding to the display box 722 is also updated by a slice imagecorresponding to the thumbnail image 6101.

Moreover, since the thumbnail image of the retrieval query imagedisplayed in the 1st-row, 1st-column display box 721 should be comparedto a thumbnail image of a similar case, the thumbnail image of theretrieval query image is desirably not updated by the thumbnail image ofthe similar case.

In consideration thereof, when the mouse cursor enters the display box721 in which the thumbnail image of the retrieval query image in thelayout region 720 is displayed, mark M1 indicating that a thumbnailimage cannot be dropped may be displayed as shown in FIG. 62 instead ofa mode in which a color of the display box is changed as shown in FIG.53. FIG. 62 is a diagram showing the basic screen K2 when the mark M1 isdisplayed in a display box. In the example shown in FIG. 62, the2nd-row, 2nd-column thumbnail image 6201 in the case display region 710has been selected, the mouse cursor has entered the display box 721, anda duplicate 6201X of the thumbnail image 6201 has been dragged to thedisplay box 721.

In this case, the display control unit 104 displays the mark M1 so as tooverlap with the display box 721. In addition, the display control unit104 changes the color of a frame-like region of the duplicate 6201X to acolor indicating that dropping of a thumbnail image is prohibited and,at the same time, changes the color of the display box 721 to a colorindicating that dropping of a thumbnail image is prohibited. While, forexample, red is adopted as the color indicating that dropping isprohibited, this is simply an example. Accordingly, since the thumbnailimage of the retrieval query image is displayed in the display box 721,the user can recognize that a thumbnail image cannot be displayed.

FIG. 63 is a flow chart showing a modification of FIG. 50. A differencefrom FIG. 50 is that S3410, S3420, S3710, and S3720 are newly provided.

In S3410, the input control unit 103 judges whether or not a position ofthe mouse cursor is inside the display box 721 corresponding to thediagnosis object case. When the input control unit 103 judges that theposition of the mouse cursor is inside the display box 721 (YES inS3410), as shown in FIG. 62, the display control unit 104 displays themark M1 indicating that dropping is prohibited in the display box 721and, at the same time, displays the display box 721 in a colorindicating that dropping is prohibited (S3420). Once S3420 is concluded,the process is returned to S3400. In addition, in S3410, when theposition of the mouse cursor is not inside the display box 721 (NO inS3410), the process is advanced to S3500.

In S3700, when a position at which dragging had ended is inside thelayout region 720 (YES in S3700) and the thumbnail image of a similarcase is already displayed in a display box at the position at whichdragging had ended (YES in S3700), the display box managing unit 106erases the association between the thumbnail image and the display box(S3720). For example, let us assume that the position at which dragginghad ended is the display box 722 and that a thumbnail image is alreadydisplayed in the display box 722. In this case, the display box managingunit 106 erases the slice ID that is registered in the 1st-row,2nd-column field corresponding to the display box 722 from the displaybox management information 4410.

On the other hand, when a thumbnail image is not displayed in thedisplay box at which dragging had ended (NO in S3710), the process isadvanced to S3800. In S3800, the display control unit 104 displays thedragged thumbnail image in the corresponding display box. In this case,the display box managing unit 106 registers a slice ID corresponding tothe dragged thumbnail image in a field of the corresponding display boxin the display box management information 4410.

Next, processes by the information terminal 100, the medical informationmanagement system 200, and the case retrieval system 300 when focusingon the sequence diagrams shown in FIGS. 28, 32, and 49 on an applicationlevel will be described. FIG. 64 is a sequence diagram when focusing onthe sequence diagrams shown in FIGS. 28 and 32 on an application level.In FIG. 64, same processes as in FIG. 28 are assigned same referencecharacters.

In FIGS. 64 to 66, “A” denotes a process of the medical informationmanagement application executed by the information terminal 100 and “B”denotes a process of the similar case retrieval application executed bythe information terminal 100. Hereinafter, the medical informationmanagement application will be described as “application A” and thesimilar case retrieval application will be described as “application B”.

First, the application A accepts a display request for a list ofexaminations to be diagnostic interpretation objects from a user, andtransmits the display request to the medical information managementsystem 200 (S510). Upon receiving the display request of the examinationlist, the medical information management system 200 lists examinationsfor which image-based examination has been performed but diagnosticinterpretation has not been completed, generates a list of examinationsto be diagnostic interpretation objects, and transmits the examinationlist to the application A.

Upon receiving the examination list, as shown in FIG. 29, theapplication A displays the examination list on the display 101, and whenone examination is selected by the user from the examination list(S530), the application A transmits a display request for the selectedexamination to the medical information management system 200 (S540).

The medical information management system 200 having received theexamination request transmits all slice images of all series included inthe examination ID specified by the display request to the application A(S550).

Next, as shown in FIG. 30, the application A displays a series list thatdisplays a list of information related to all series included in thespecified examination ID (S560).

Subsequently, when a series that is a diagnostic interpretation objectis selected by the user from the series list, the application A displaysa slice image at a first slice position of the selected series on themedical image viewer 610 (S570). At this point, the user inputs anoperation for slice feeding and causes a desired slice image to bedisplayed on the medical image viewer 610.

Next, the application A accepts an operation for setting a region ofinterest in the slice image displayed on the medical image viewer 610from the user (S580).

Subsequently, the application A generates region of interest informationrepresenting the region of interest set by the user and transmits theregion of interest information together with a slice image (slice imageof the diagnosis object case) in which the region of interest is set tothe application B (S590, S600).

Next, upon receiving the slice image and the region of interestinformation of the diagnosis object case, the application B transmitsthe slice image and the region of interest information to the caseretrieval system 300 (S601, S602).

Upon receiving the slice image and the region of interest information,the case retrieval system 300 executes the processes of S610 to S640 ina similar manner to FIG. 32.

Subsequently, the application B generates an initial basic screen usingthe similar case data transmitted in S640 and the display box managementinformation 4410 (S670). In addition, the application B executes theprocess of S670 that is shown in detail in FIG. 33.

FIG. 65 is a sequence diagram when focusing on the sequence diagramshown in FIG. 49 on an application level. In FIG. 65, same processes asin FIG. 49 are assigned same reference characters.

In S800 shown in FIG. 65, the application B senses a movement of athumbnail image of a similar case to a display box. Details of theprocess of S800 have been described in FIG. 50.

Next, the application B refers to the similar case data 4000 (FIG. 26)of the thumbnail image displayed in the display box, registers a sliceID corresponding to the thumbnail image in the display box managementinformation 4410 (FIG. 44), and updates the display box managementinformation 4410 (S810).

Subsequently, the application B transmits the slide ID of the thumbnailimage moved to the display box to the application A (S820).

Upon receiving the slide ID (S820), the application A transmits theslice ID to the medical information management system 200 (S821).

Subsequently, the medical information management system 200 executes theprocesses of S830 and S840 in a similar manner to FIG. 49.

In S850, when the application A receives all slice images of acorresponding series, the application A displays the slice images on acorresponding medical image viewer.

FIG. 66 is a sequence diagram which focuses, on an application level, ona process when a thumbnail image of a similar case isdragged-and-dropped in the information terminal 100.

S603 and S604 are not included in FIG. 64 while these steps are includedin FIG. 66. In FIG. 66, an image feature is extracted by the informationterminal 100. Therefore, the application B extracts an image featurefrom a region of interest set in the slice image of the diagnosis objectcase (S603) and transmits the extracted image feature to the caseretrieval system 300 (S604).

Next, a process when a lesion distribution displayed in the distributionlist display region 750 shown in FIG. 11 is selected will be described.FIG. 67 is a flow chart showing a process when a lesion distributiondisplayed in the distribution list display region 750 is selected.

In S2000, when the input control unit 103 senses an operation forselecting any one distribution check item among lesion distribution(distribution check items) displayed in the distribution list displayregion 750, the display control unit 104 judges which of first to thirddistribution information the sensed distribution check item correspondsto. In the case of the first distribution information, the process isadvanced to S1301, in the case of the second distribution information,the process is advanced to S1302, and in the case of the thirddistribution information, the process is advanced to S1303.

The first distribution information is information for selecting athumbnail image, in which a size of a region of interest belongs to aprescribed first range, from among thumbnail images of similar casesthat are displayed as a list in the case display region 710. Theprescribed first range indicates that the size of the region of interestis larger than a lung region. In this case, “bilateral”, “multiple”,“diffuse”, and “hematogenous” correspond to the first distributioninformation. Therefore, a value range to which a size of a region ofinterest, which is set when diagnosing such lesion distribution, belongsis adopted as the first range.

The second distribution information is information for selecting athumbnail image, in which a size of a region corresponding to a regionof interest belongs to a prescribed second range (lower than the firstrange, that is, an upper limit value of the second range is not morethan a lower limit value of the first range), from among thumbnailimages of similar cases that are displayed as a list in the case displayregion 710. The prescribed second range indicates that a size of aregion corresponding to a region of interest is a part of a lung region.In this case, “bronchial” and “segmental” correspond to the seconddistribution information. Therefore, a value range to which a size of aregion of interest, which is set when diagnosing such lesiondistribution, belongs is adopted as the second range.

The third distribution information is information for selecting athumbnail image, in which a region of interest includes the pleura, fromamong thumbnail images of similar cases that are displayed as a list inthe case display region 710. In this case, “subpleural” corresponds tothe third distribution information.

In S1301, the display control unit 104 extracts, in a descending orderof degrees of similarity, similar cases whose number is not more than amaximum displayable number (20 in the present embodiment) of thumbnailimages in the case display region 710 among similar cases which havebeen obtained as a result of a similar case retrieval and which aresimilar cases of the lesion distribution selected by the user as thefirst distribution information. The display control unit 104 decides thenumber of the extracted similar cases as a number NZ1 of similar casesthat are magnification objects. In addition, the display control unit104 decides that a thumbnail image of an extracted similar case i (i isan index specifying the extracted similar cases and is an integer notless than 1) is a thumbnail image of a processing object. Subsequently,the display control unit 104 repeats the processes of S2100 and S1501until the index i reaches NZ1. The display control unit 104 incrementsthe index i by 1 each time the processes of S2100 and S1501 areexecuted. Once the index i exceeds NZ1 (NO in S1301), the process isfinished.

In S2100, the display control unit 104 calculates a first magnificationratio corresponding to the first distribution information with respectto the similar case i. In this case, as the first magnification ratio,for example, 1.0 is adopted. However, this is simply an example and amagnification ratio other than 1.0 may be adopted as the firstmagnification ratio as long as the magnification ratio is a value thatenables an entire region of interest that is set when diagnosing alesion distribution representing the first distribution information tofit inside the display region.

In S1501, the display control unit 104 magnifies the thumbnail images ofthe i-number of similar cases at the first magnification ratio of thei-number of similar cases.

FIG. 68 is a diagram showing the basic screen K2 when the firstdistribution information is selected. In FIG. 68, bilateral is selected.In this case, only thumbnail images of similar cases whose lesiondistribution corresponds to bilateral among the similar cases aredisplayed in the case display region 710. In addition, in this case,since the magnification ratio is 1.0, the thumbnail images are displayedin the case display region 710 in a same display mode as the thumbnailimages displayed immediately after the similar retrieval result isobtained. In other words, the thumbnail images are displayed without adisplay position of the thumbnail images being adjusted so that a centerof a region of interest ROI is positioned at a center of a displayregion 6801 and without being magnified.

In S1302, the display control unit 104 extracts, in a descending orderof degrees of similarity, similar cases whose number is not more than amaximum displayable number of thumbnail images in the case displayregion 710 among similar cases which have been obtained as a result of asimilar case retrieval and which are similar cases of the lesiondistribution selected by the user as the second distributioninformation. The display control unit 104 decides the number of theextracted similar cases as a number NZ2 of similar cases that aremagnification objects. In addition, the display control unit 104 decidesthat a thumbnail image of an extracted similar case i is a thumbnailimage of a processing object. Subsequently, the display control unit 104repeats the processes of S2200 and S1502 until the index i reaches NZ2.The display control unit 104 increments the index i by 1 each time theprocesses of S2200 and S1502 are executed. Once the index i exceeds NZ2(NO in S1302), the process is finished.

In S2200, the display control unit 104 calculates a second magnificationratio corresponding to the second distribution information with respectto the similar case i using a size of a display region determined inadvance for one thumbnail image in the case display region 710 and theregion of interest information of the similar case i.

When the second distribution information is selected, the similar case iis magnified so that a size of the region of interest is around ½ of asize of the display region. Therefore, the display control unit 104calculates a second magnification ratio ki with respect to the similarcase i using, for example, the mathematical expression given below. Ifan area of the display region is denoted by Sd and an area of the regionof interest of the thumbnail image of the similar case i that ismagnification object is denoted by Si, then the second magnificationratio ki can be calculated by the following equation.

ki=½(Sd/Si)

In S1502, the display control unit 104 magnifies the thumbnail image ofthe similar case i by the second magnification ratio ki and displaysthumbnail images in the case display region 710 so that a center of theregion of interest of the thumbnail images is positioned at a center ofthe display region.

FIG. 69 is a diagram showing the basic screen K2 when the seconddistribution information is selected. In FIG. 69, bronchial is selected.In this case, only thumbnail images of similar cases whose lesiondistribution corresponds to bronchial among the similar cases aredisplayed in the case display region 710. In addition, in the casedisplay region 710, all thumbnail images have been magnified at thesecond magnification ratio so that the center of the region of interestROI is positioned at the center of the display region 6901.

In S1303, the display control unit 104 extracts, in a descending orderof degrees of similarity, similar cases whose number is not more than amaximum displayable number of thumbnail images in the case displayregion 710 among similar cases which have been obtained as a result of asimilar case retrieval and which are similar cases of the lesiondistribution selected by the user as the third distribution information.The display control unit 104 decides the number of the extracted similarcases as a number NZ3 of similar cases that are magnification objects.In addition, the display control unit 104 decides that a thumbnail imageof the extracted similar case i is a thumbnail image of a processingobject. Subsequently, the display control unit 104 repeats the processesof S2300 and S1503 until the index i reaches NZ3. The display controlunit 104 increments the index i by 1 each time the processes of S2300and S1503 are executed. Once the index i exceeds NZ3 (NO in S1303), theprocess is finished.

In S2300, the display control unit 104 calculates a third magnificationratio corresponding to the third distribution information with respectto the similar case i using a size of a display region determined inadvance for one thumbnail image in the case display region 710, theregion of interest information of the similar case i, and pleural regioninformation 4900.

FIG. 72 is a diagram showing a data configuration of similar case data4000 to which the pleural region information 4900 has been added.Moreover, when the pleural region information 4900 is not registered inthe similar case data 4000, the pleural region information 4900 cannotbe obtained. In this case, the display control unit 104 need only setthe third magnification ratio to 1.0 which is the same value as thefirst magnification ratio. The pleural region information 4900 isinformation indicating a pleural region in a similar case.

In S1503, the display control unit 104 magnifies the thumbnail image ofthe similar case i by the third magnification ratio ki and displaysthumbnail images in the case display region 710 so that a center of theregion of interest of the thumbnail images is positioned at a center ofthe display region.

FIG. 71 is a diagram for describing a pleural region 7101. As shown inFIG. 71, the pleural region 7101 is a region which includes a pleura,whose center is positioned at a center of the region of interest ROI,and which has a rectangular shape slightly larger in size than theregion of interest ROI. In this case, the pleural region information4900 is constituted by four values including coordinates (xpl, ypt) of atop left vertex and coordinates (xrp, ypb) of a bottom right vertex ofthe pleural region 7101. When the third distribution information isselected, in order to display a magnified pleural region, the displaycontrol unit 104 calculates the third magnification ratio ki using themathematical expression given below. If an area of the display region7102 is denoted by Sd and an area of the pleural region 7101 is denotedby Sp, then the third magnification ratio ki can be calculated by thefollowing equation.

ki=Sd/Sp

Moreover, the pleural region information 4900 may be input by the usertogether with region of interest information when creating the similarcase data 4000. Alternatively, the pleural region information 4900 maybe automatically created by having an image processing apparatusautomatically extract a lung region from a slice image and judge apleural position.

FIG. 70 is a diagram showing the basic screen K2 when the thirddistribution information is selected. In FIG. 70, subpleural isselected. In this case, only thumbnail images of similar cases whoselesion distribution corresponds to subpleural among the similar casesare displayed in the case display region 710. In addition, in the casedisplay region 710, all thumbnail images have been magnified at thethird magnification ratio so that the center of the region of interestROI is positioned at the center of the display region 7001.

According to the process described above, thumbnail images are displayedin the case display region 710 at a magnification ratio that reflectscontents of diagnosis with respect to lesion distribution. In addition,the thumbnail images are displayed in the case display region 710 whilemaking sizes of regions of interest uniform. Therefore, an occurrence ofa situation where a region of interest is magnified at a lowmagnification ratio in a part of the similar medical images and theregion of interest is overlooked can be prevented and diagnosticaccuracy can be improved. Furthermore, since the magnification processis only performed on the similar cases displayed in the case displayregion 710 instead of on all of the similar cases obtained by similarcase retrieval, a load on the system can be significantly reduced.

INDUSTRIAL APPLICABILITY

The present disclosure can be used in a similar case retrieval apparatusfor presenting similar cases to be used as a reference when diagnosing amedical image that is a diagnostic interpretation object, a diagnosticinterpretation teaching apparatus for diagnostic interpretation interns,and the like.

What is claimed is:
 1. A control method of an information terminal,which is connected to a medical information management system thatmanages medical images that are diagnostic interpretation objectcandidates, and which is connected to a case retrieval system thatrefers to a medical image database in which medical images areregistered and retrieves a medical image, and moreover which includes adisplay, one medical image that is a diagnostic interpretation objectselected from the diagnostic interpretation object candidates managed bythe medical information management system being displayed on thedisplay, the control method causing a computer of the informationterminal to: sense specification information indicating a region ofinterest in the medical image; receive from the case retrieval systemone or more similar medical images each having a prescribed degree ofsimilarity with a feature quantity of the region of interest indicatedby the specification information in accordance with the region ofinterest; display the medical image that is managed by the medicalinformation management system in a first display region of a firstdisplay screen that is displayed on the display and display thumbnailviews of a plurality of similar medical images received from the caseretrieval system in a second display region that differs from the firstdisplay region of the first display screen, the first display regionincluding a first display box for displaying the medical image and asecond display box for displaying a first similar medical image selectedfrom the similar medical images displayed in thumbnail views in thesecond display region, the first display box and the second display boxbeing adjacent to each other; and when sensing an operation for movingthe first similar medical image among the similar medical imagesdisplayed in thumbnail views in the second display region to the seconddisplay box, display the first similar medical image in the seconddisplay box and display the first similar medical image so as to beadjacent to the medical image; wherein when it is sensed that a firstsimilar medical image selected from the plurality of similar medicalimages included in the second display region is moved to a seconddisplay box included in the first display region, a second displayscreen on which the medical image and the first similar medical imageare arranged in contrast with each other is displayed separately fromthe first display screen.
 2. The control method according to claim 1,wherein when it is sensed that a second similar medical image among theplurality of similar medical images included in the second displayregion is moved to the first display region in a state where the firstsimilar medical image is included in the first display region, the firstsimilar medical image displayed on the second display screen is switchedto the second similar medical image.
 3. The control method according toclaim 2, wherein the second display box exists in plurality, and when itis sensed that the second similar medical image has been moved to asecond display box in which the first similar medical image is displayedso that the second similar medical image overlaps with the seconddisplay box, the first similar medical image displayed in the seconddisplay box is switched to the second similar medical image, and when itis sensed that the second similar medical image has been moved to asecond display box in which the first similar medical image is notdisplayed, the second similar medical image is displayed in the seconddisplay box.
 4. The control method according to claim 1, wherein thefirst display screen includes a third display region that displays asimilar medical image previously included in the first display region,the first display region includes a prescribed number of display boxesincluding the first display box and the second display box, and when thenumber of similar medical images moved from the second display region tothe first display region exceeds the prescribed number, the similarmedical image included in the first display region is moved to the thirddisplay region.
 5. The control method according to claim 2, wherein thefirst display screen includes a third display region that displays asimilar medical image previously included or currently included in thefirst display region, the first display region includes a prescribednumber of display boxes including the first display box and the seconddisplay box, when the number of similar medical images moved from thesecond display region to the first display region is equal to or smallerthan the prescribed number, the moved similar medical image is displayedin the first display region and the third display region, and when thenumber of similar medical images moved from the second display region tothe first display region exceeds the prescribed number, the similarmedical image included in the first display region is moved to the thirddisplay region.
 6. The control method according to claim 4, wherein adisplay size of a similar medical image in the third display region isset smaller than a display size of a similar medical image in the firstdisplay region and the second display region.
 7. The control methodaccording to claim 1, wherein a display arrangement of the seconddisplay screen is the same as a display arrangement of a first displayregion that is included in the first display screen.
 8. The controlmethod according to claim 1, wherein the display includes a firstdisplay and a second display, and the first display screen is displayedon the first display and the second display screen is displayed on thesecond display.
 9. The control method according to claim 1, whereindisease name information on a lesion represented in a medical image thatis a diagnostic interpretation object is not set in additionalinformation of the medical image, and disease name information on alesion represented in each of the plurality of received similar medicalimages is set in additional information of each of the plurality ofreceived similar medical images.
 10. The control method according toclaim 1, wherein the second display region includes a prescribed numberof display frames, and images of the prescribed number or less among theplurality of received similar medical images are displayed in each ofthe display frames in a descending order of degrees of similarity withthe medical image that is a diagnostic interpretation object.
 11. Thecontrol method according to claim 1, wherein the control method causesthe computer of the information terminal to: transmit informationindicating the feature quantity of the region of interest to the caseretrieval system; and receive the similar medical image having theprescribed degree of similarity with the feature quantity of the regionof interest from the case retrieval system.
 12. The control methodaccording to claim 1, wherein the control method causes the computer ofthe information terminal to: transmit the one medical image that is adiagnostic interpretation object and specification informationindicating the region of interest to the case retrieval system; andreceive, from the case retrieval system, the similar medical imagehaving the prescribed degree of similarity with the feature quantity ofthe region of interest obtained from the medical image that is adiagnostic interpretation object and the specification information. 13.The control method according to claim 1, wherein the one medical imagethat is a diagnostic interpretation object is a medical image of a lung,the similar medical image is a medical image of a lung, the firstdisplay screen includes first distribution information for selecting asimilar medical image in which a size of a region corresponding to theregion of interest belongs to a prescribed first range, the first rangeindicating that the size of the region corresponding to the region ofinterest is wider than a prescribed range in a region of the lung,second distribution information for selecting a similar medical image inwhich the size of the region corresponding to the region of interestbelongs to a prescribed second range, the second range being lower thanthe first range and indicating that the size of the region correspondingto the region of interest is a part of a region of the lung, and thirddistribution information for selecting a similar medical image in whichthe region corresponding to the region of interest includes a pleura,and when any one of the first to third items of distribution informationis selected, a similar medical image corresponding to the selecteddistribution information is displayed in the second display region. 14.The control method according to claim 13, wherein when selection of thefirst distribution information is sensed, a similar medical imagecorresponding to the first distribution information is displayed in acorresponding display region at an initial display size, when selectionof the second distribution information is sensed, a similar medicalimage corresponding to the second distribution information is magnifiedand displayed in a corresponding display region so as to be centered onthe region corresponding to the region of interest in the similarmedical image corresponding to the second distribution information, andwhen selection of the third distribution information is sensed, asimilar medical image corresponding to the third distributioninformation is magnified and displayed in a corresponding display regionin a state where the pleura is included so as to be centered on theregion corresponding to the region of interest in the similar medicalimage corresponding to the third distribution information.
 15. Thecontrol method according to claim 13, wherein the first distributioninformation is information indicating a distribution belonging to abilateral, a multiple, a diffuse, or a hematogenous category, the seconddistribution information is information indicating a distributionbelonging to a segmental or a bronchial category, and the thirddistribution information is information indicating a distributionbelonging to a subpleural category.
 16. A non-transitorycomputer-readable recording medium which stores a program that isexecuted on an information terminal, which is connected to a medicalinformation management system that manages medical images that arediagnostic interpretation object candidates, and which is connected to acase retrieval system that refers to a medical image database in whichmedical images are registered and retrieves a medical image, andmoreover which includes a display, one medical image that is adiagnostic interpretation object selected from the diagnosticinterpretation object candidates managed by the medical informationmanagement system being displayed on the display, the program causing acomputer of the information terminal to: sense specification informationindicating a region of interest in the medical image; receive from thecase retrieval system one or more similar medical images each having aprescribed degree of similarity with a feature quantity of the region ofinterest indicated by the specification information in accordance withthe region of interest; display the medical image that is managed by themedical information management system in a first display region of afirst display screen that is displayed on the display and displaythumbnail views of a plurality of similar medical images received fromthe case retrieval system in a second display region that differs fromthe first display region of the first display screen, the first displayregion including a first display box for displaying the medical imageand a second display box for displaying a first similar medical imageselected from the similar medical images displayed in thumbnail views inthe second display region, the first display box and the second displaybox being adjacent to each other; and when sensing an operation formoving the first similar medical image among the similar medical imagesdisplayed in thumbnail views in the second display region to the seconddisplay box, display the first similar medical image in the seconddisplay box and display the first similar medical image so as to beadjacent to the medical image; wherein when it is sensed that a firstsimilar medical image selected from the plurality of similar medicalimages included in the second display region is moved to a seconddisplay box included in the first display region, a second displayscreen on which the medical image and the first similar medical imageare arranged in contrast with each other is displayed separately fromthe first display screen.